What is the Internet
From Wikipedia, the free encyclopedia
This article is about the
worldwide computer network. For other uses, see Internet (disambiguation).
Internet
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Computer network types
by spatial scope |
·
Internet
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The Internet is the global
system of interconnected computer networks that use the Internet protocol suite (TCP/IP) to link devices
worldwide. It is a network of networks that consists of
private, public, academic, business, and government networks of local to global
scope, linked by a broad array of electronic, wireless, and optical networking
technologies. The Internet carries an unlimited range of information resources
and services, such as the inter-linked hypertext documents and applications of the World Wide Web (WWW), electronic mail, telephony, and file sharing.
The origins of the Internet date back to
research commissioned by the United States Federal Government in the 1960s to
build robust, fault-tolerant communication via computer networks.[1] The linking of
commercial networks and enterprises in the early 1990s marked the beginning of
the transition to the modern Internet,[2] and generated rapid
growth as institutional, personal, and mobile computers were
connected to the network. By the late 2000s, its services and
technologies had been incorporated into virtually every aspect of modern life.
Most traditional communications media,
including telephony, radio, television, paper mail and newspapers are being
reshaped, redefined, or even bypassed by the Internet, giving birth to new
services such as email, Internet telephony, Internet television, online music, digital newspapers,
and video
streaming websites.
Newspaper, book, and other print publishing are adapting to websitetechnology, or are
reshaped into blogging, web feeds and online news aggregators. The Internet has
enabled and accelerated new forms of personal interactions through instant messaging, Internet forums, and social networking. Online shopping has grown
exponentially both for major retailers and small businesses and entrepreneurs, as it enables firms to
extend their "brick and mortar" presence to serve
a larger market or even sell goods and services
entirely online. Business-to-business and financial services on the Internet
affect supply
chains across
entire industries.
The Internet has no centralized governance
in either technological implementation or policies for access and usage; each
constituent network sets its own policies.[3] Only the overreaching
definitions of the two principal name spaces in the Internet,
the Internet
Protocol address (IP address) space and the Domain Name System (DNS), are directed
by a maintainer organization, the Internet Corporation for
Assigned Names and Numbers (ICANN). The technical underpinning
and standardization of the core protocols is an activity of the Internet Engineering Task Force (IETF), a
non-profit organization of loosely affiliated international participants that
anyone may associate with by contributing technical expertise.[4]
Contents
[hide]
Terminology
When the term Internet is
used to refer to the specific global system of interconnected Internet Protocol (IP) networks, the
word is a proper
noun[5] that should be
written with an initial capital letter. In common use and the
media, it is often erroneously not capitalized, viz. the internet. Some
guides specify that the word should be capitalized when used as a noun, but not
capitalized when used as an adjective.[6] The Internet is
also often referred to as the Net, as a short form of network.
Historically, as early as 1849, the word internetted was used
uncapitalized as an adjective, meaning interconnected or interwoven.[7] The designers of
early computer networks used internet both as a noun and as a
verb in shorthand form of internetwork or internetworking,
meaning interconnecting computer networks.[8]
The terms Internet and World
Wide Web are often used interchangeably in everyday speech; it is
common to speak of "going on the Internet" when using a web browser to view web pages. However, the World Wide Web or the Web is
only one of a large number of Internet services. The Web is a collection of
interconnected documents (web pages) and other web resources, linked by hyperlinks and URLs.[9] As another point of
comparison, Hypertext Transfer Protocol, or HTTP, is the
language used on the Web for information transfer, yet it is just one of many
languages or protocols that can be used for communication on the Internet.[10] The term Interweb is a portmanteau of Internet and World
Wide Web typically used sarcastically to parody a technically unsavvy
user.
History
Research into packet switching by Paul Baran and Donald Davies emerged in the
early to mid-1960s,[11] and packet switched
networks such as the NPL network,[12] ARPANET, Tymnet, the Merit Network,[13] Telenet, and CYCLADES,[14][15] were developed in
the late 1960s and 1970s using a variety of protocols.[16] The ARPANET project
led to the development of protocols for internetworking, by which multiple
separate networks could be joined into a single network of networks.[17] ARPANET development
began with two network nodes which were interconnected between the Network
Measurement Center at the University of California, Los Angeles (UCLA) Henry Samueli School of
Engineering and Applied Science directed by Leonard Kleinrock, and the NLS system
at SRI International (SRI) by Douglas Engelbart in Menlo Park, California, on 29
October 1969.[18] The third site was
the Culler-Fried Interactive Mathematics Center at the University of California, Santa Barbara, followed by the University of Utah Graphics
Department. In an early sign of future growth, fifteen sites were connected to
the young ARPANET by the end of 1971.[19][20] These early years
were documented in the 1972 film Computer Networks: The
Heralds of Resource Sharing.
Early international collaborations on the
ARPANET were rare. European developers were concerned with developing the X.25 networks.[21] Notable exceptions
were the Norwegian Seismic Array (NORSAR) in June 1973, followed
in 1973 by Sweden with satellite links to the Tanum Earth Station and Peter T. Kirstein's research group in the
United Kingdom, initially at the Institute of Computer Science, University of London and later at University College London.[22][23][24] In December
1974, RFC 675 (Specification
of Internet Transmission Control Program), by Vinton Cerf, Yogen Dalal, and
Carl Sunshine, used the term internet as a shorthand for internetworking and
later RFCs repeated this use.[25]Access to the ARPANET was
expanded in 1981 when the National Science Foundation (NSF) funded
the Computer Science Network (CSNET). In 1982,
the Internet Protocol Suite(TCP/IP) was
standardized, which permitted worldwide proliferation of interconnected
networks.
T3 NSFNET Backbone, c.
1992.
TCP/IP network access expanded again in
1986 when the National Science Foundation Network (NSFNet) provided
access to supercomputer sites in the United
States for researchers, first at speeds of 56 kbit/s and later at 1.5 Mbit/s
and 45 Mbit/s.[26] Commercial Internet service providers (ISPs) emerged in
the late 1980s and early 1990s. The ARPANET was decommissioned in 1990. By
1995, the Internet was fully commercialized in the U.S. when the NSFNet was
decommissioned, removing the last restrictions on use of the Internet to carry
commercial traffic.[27] The Internet
rapidly expanded in Europe and Australia in the mid to late 1980s[28][29] and to Asia in the
late 1980s and early 1990s.[30] The beginning of
dedicated transatlantic communication between the NSFNET and
networks in Europe was established with a low-speed satellite relay
between Princeton University and Stockholm, Sweden in December 1988.[31] Although other
network protocols such as UUCP had global reach
well before this time, this marked the beginning of the Internet as an
intercontinental network.
Public commercial use of the Internet began
in mid-1989 with the connection of MCI Mail and Compuserve's email capabilities to
the 500,000 users of the Internet.[32] Just months later
on 1 January 1990, PSInet launched an
alternate Internet backbone for commercial use; one of the networks that would
grow into the commercial Internet we know today. In March 1990, the first
high-speed T1 (1.5 Mbit/s) link between the NSFNET and Europe was installed
between Cornell University and CERN, allowing much more
robust communications than were capable with satellites.[33] Six months
later Tim
Berners-Lee would
begin writing WorldWideWeb, the first web browser after two years of
lobbying CERN management. By Christmas 1990, Berners-Lee had built all the
tools necessary for a working Web: the HyperText Transfer Protocol (HTTP) 0.9,[34] the HyperText Markup Language (HTML), the first
Web browser (which was also a HTML editor and could
access Usenet newsgroups
and FTP files), the first
HTTP server software(later known as CERN httpd), the first web server,[35] and the first Web
pages that described the project itself. In 1991 the Commercial Internet eXchange was founded, allowing
PSInet to communicate with the other commercial networks CERFnet and Alternet.
Since 1995 the Internet has tremendously impacted culture and commerce,
including the rise of near instant communication by email, instant messaging, telephony (Voice over Internet Protocol or VoIP), two-way interactive video
calls,
and the World
Wide Web[36] with its discussion forums, blogs, social networking, and online shopping sites. Increasing
amounts of data are transmitted at higher and higher speeds over fiber optic
networks operating at 1-Gbit/s, 10-Gbit/s, or more.
2005
|
2010
|
2016a
|
|
6.5 billion
|
6.9 billion
|
7.3 billion
|
|
Users worldwide
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16%
|
30%
|
47%
|
Users in the developing world
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8%
|
21%
|
40%
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Users in the developed world
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51%
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67%
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81%
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The Internet continues to grow, driven by
ever greater amounts of online information and knowledge, commerce,
entertainment and social networking.[39] During the late
1990s, it was estimated that traffic on the public Internet grew by 100 percent
per year, while the mean annual growth in the number of Internet users was
thought to be between 20% and 50%.[40] This growth is
often attributed to the lack of central administration, which allows organic
growth of the network, as well as the non-proprietary nature of the Internet
protocols, which encourages vendor interoperability and prevents any one
company from exerting too much control over the network.[41] As of 31 March
2011, the estimated total number of Internet users was
2.095 billion (30.2% of world population).[42] It is estimated
that in 1993 the Internet carried only 1% of the information flowing through
two-way telecommunication, by 2000 this figure had grown to 51%, and by 2007
more than 97% of all telecommunicated information was carried over the
Internet.[43]
Governance
The Internet is a global network that comprises many
voluntarily interconnected autonomous networks. It operates without a central
governing body. The technical underpinning and standardization of the core
protocols (IPv4 and IPv6) is an activity of
the Internet Engineering Task Force (IETF), a
non-profit organization of loosely affiliated international participants that
anyone may associate with by contributing technical expertise. To maintain
interoperability, the principal name spaces of the Internet are
administered by the Internet Corporation for
Assigned Names and Numbers (ICANN). ICANN is governed by an
international board of directors drawn from across the Internet technical,
business, academic, and other non-commercial communities. ICANN coordinates the
assignment of unique identifiers for use on the Internet, including domain names, Internet Protocol (IP)
addresses, application port numbers in the transport protocols, and many other
parameters. Globally unified name spaces are essential for maintaining the
global reach of the Internet. This role of ICANN distinguishes it as perhaps
the only central coordinating body for the global Internet.[44]
Regional Internet Registries (RIRs) allocate IP
addresses:
·
Latin American and
Caribbean Internet Addresses Registry (LACNIC) for Latin America and the Caribbean region
·
Réseaux
IP Européens – Network Coordination Centre (RIPE NCC)
for Europe, the Middle East, and Central Asia
The National
Telecommunications and Information Administration, an agency of the United States Department of Commerce, had final approval over
changes to the DNS
root zoneuntil
the IANA stewardship transition on 1 October 2016.[45][46][47][48] The Internet Society (ISOC) was founded
in 1992 with a mission to "assure the open development, evolution
and use of the Internet for the benefit of all people throughout the
world".[49] Its members include
individuals (anyone may join) as well as corporations, organizations, governments, and
universities. Among other activities ISOC provides an administrative home for a
number of less formally organized groups that are involved in developing and
managing the Internet, including: the Internet Engineering Task Force (IETF), Internet Architecture Board (IAB), Internet Engineering Steering Group (IESG), Internet Research Task Force (IRTF), and Internet Research Steering Group (IRSG). On 16
November 2005, the United Nations-sponsored World Summit on the Information Society in Tunis established
the Internet Governance Forum (IGF) to discuss
Internet-related issues.
Infrastructure
See also: List of countries by
number of Internet users and List of countries by Internet
connection speeds
2007 map showing
submarine fiberoptic telecommunication cables around the world.
The communications infrastructure of the
Internet consists of its hardware components and a system of software layers
that control various aspects of the architecture.
Routing
and service tiers
Packet routing across the
Internet involves several tiers of Internet service providers.
Internet service providers establish the
worldwide connectivity between individual networks at various levels of scope.
End-users who only access the Internet when needed to perform a function or
obtain information, represent the bottom of the routing hierarchy. At the top
of the routing hierarchy are the tier 1 networks, large telecommunication
companies that exchange traffic directly with each other via peeringagreements. Tier 2 and lower level
networks buy Internet transit from other
providers to reach at least some parties on the global Internet, though they
may also engage in peering. An ISP may use a single upstream provider for
connectivity, or implement multihoming to achieve
redundancy and load balancing. Internet exchange points are major traffic
exchanges with physical connections to multiple ISPs. Large organizations, such
as academic institutions, large enterprises, and governments, may perform the
same function as ISPs, engaging in peering and purchasing transit on behalf of
their internal networks. Research networks tend to interconnect with large
subnetworks such as GEANT, GLORIAD, Internet2, and the UK's national research and education network, JANET. Both the Internet IP
routing structure and hypertext links of the World Wide Web are examples
of scale-free networks.[50] Computers and
routers use routing
tables in
their operating system to direct IP packets to the next-hop
router or destination. Routing tables are maintained by manual configuration or
automatically by routing protocols. End-nodes typically use
a default
route that
points toward an ISP providing transit, while ISP routers use the Border Gateway Protocol to establish the
most efficient routing across the complex connections of the global Internet.
Access
Common methods of Internet access by users include
dial-up with a computer modem via telephone
circuits, broadband over coaxial cable, fiber optics or copper
wires, Wi-Fi, satellite and cellular telephone technology (3G, 4G). The Internet may often
be accessed from computers in libraries and Internet cafes. Internet access points exist in many
public places such as airport halls and coffee shops. Various terms are used,
such as public Internet kiosk, public access terminal,
and Web payphone. Many hotels also have
public terminals, though these are usually fee-based. These terminals are
widely accessed for various usages, such as ticket booking, bank deposit, or
online payment. Wi-Fi provides wireless access to the Internet via local
computer networks. Hotspots providing such
access include Wi-Fi cafes, where users need to
bring their own wireless devices such as a laptop or PDA. These services may be
free to all, free to customers only, or fee-based.
Grassroots efforts have led
to wireless community networks. Commercial Wi-Fi
services covering large city areas are in place in New York, London, Vienna, Toronto, San Francisco, Philadelphia, Chicago and Pittsburgh. The Internet can then
be accessed from such places as a park bench.[51] Apart from Wi-Fi,
there have been experiments with proprietary mobile wireless networks
like Ricochet, various high-speed data
services over cellular phone networks, and fixed wireless services. High-end
mobile phones such as smartphones in general come with
Internet access through the phone network. Web browsers such as Opera are available on these advanced
handsets, which can also run a wide variety of other Internet software. More
mobile phones have Internet access than PCs, though this is not as widely used.[52] An Internet access
provider and protocol matrix differentiates the methods used to get online.
Protocols
Guarantee ?
|
||||||
Loss
|
Order
|
Timing
|
||||
Internet
|
best effort
|
none
|
no
|
no
|
no
|
no (inferred via loss)
|
constant rate
|
yes
|
yes
|
yes
|
no congestion
|
||
guarantee rate
|
yes
|
yes
|
yes
|
no congestion
|
||
guarantee minimum
|
no
|
yes
|
no
|
yes
|
||
none
|
no
|
yes
|
no
|
no
|
|
|
While the hardware components in the
Internet infrastructure can often be used to support other software systems, it
is the design and the standardization process of the software that
characterizes the Internet and provides the foundation for its scalability and
success. The responsibility for the architectural design of the Internet
software systems has been assumed by the Internet Engineering Task Force (IETF).[53] The IETF conducts
standard-setting work groups, open to any individual, about the various aspects
of Internet architecture. Resulting contributions and standards are published
as Request for Comments (RFC) documents on
the IETF web site. The principal methods of networking that enable the Internet
are contained in specially designated RFCs that constitute the Internet Standards. Other less rigorous
documents are simply informative, experimental, or historical, or document the
best current practices (BCP) when implementing Internet technologies.
The Internet standards describe a framework
known as the Internet protocol suite. This is a model
architecture that divides methods into a layered system of protocols,
originally documented in RFC 1122 and RFC 1123. The layers correspond
to the environment or scope in which their services operate. At the top is
the application layer, space for the
application-specific networking methods used in software applications. For
example, a web browser program uses the client-server application model
and a specific protocol of interaction between servers and clients, while many
file-sharing systems use a peer-to-peer paradigm. Below
this top layer, the transport layer connects
applications on different hosts with a logical channel through the network with
appropriate data exchange methods.
Underlying these layers are the networking
technologies that interconnect networks at their borders and exchange traffic
across them. The Internet layer enables computers
to identify and locate each other via Internet Protocol (IP)
addresses,
and routes their traffic via intermediate (transit) networks. Last, at the
bottom of the architecture is the link layer, which provides logical
connectivity between hosts on the same network link, such as a local area network (LAN) or a dial-up connection. The model, also known
as TCP/IP, is designed to be
independent of the underlying hardware used for the physical connections, which
the model does not concern itself with in any detail. Other models have been
developed, such as the OSI model, that attempt to be
comprehensive in every aspect of communications. While many similarities exist
between the models, they are not compatible in the details of description or
implementation. Yet, TCP/IP protocols are usually included in the discussion of
OSI networking.
As user data is processed
through the protocol stack, each abstraction layer adds encapsulation
information at the sending host. Data is transmitted over the wire at
the link level between hosts and routers. Encapsulation is removed by the
receiving host. Intermediate relays update link encapsulation at each hop, and
inspect the IP layer for routing purposes.
The most prominent component of the
Internet model is the Internet Protocol (IP), which provides addressing
systems, including IP addresses, for computers on the
network. IP enables internetworking and, in essence, establishes the Internet
itself. Internet Protocol Version
4 (IPv4)
is the initial version used on the first generation of the Internet and is
still in dominant use. It was designed to address up to ~4.3 billion (109) hosts. However, the
explosive growth of the Internet has led to IPv4 address exhaustion, which entered its final
stage in 2011,[54] when the global address
allocation pool was exhausted. A new protocol version, IPv6, was developed in
the mid-1990s, which provides vastly larger addressing capabilities and more
efficient routing of Internet traffic. IPv6 is currently in
growing deployment around the world,
since Internet address registries (RIRs) began to urge all
resource managers to plan rapid adoption and conversion.[55]
IPv6 is not directly interoperable by
design with IPv4. In essence, it establishes a parallel version of the Internet
not directly accessible with IPv4 software. Thus, translation facilities must
exist for internetworking or nodes must have duplicate networking software for
both networks. Essentially all modern computer operating systems support both
versions of the Internet Protocol. Network infrastructure, however, has been
lagging in this development. Aside from the complex array of physical
connections that make up its infrastructure, the Internet is facilitated by bi-
or multi-lateral commercial contracts, e.g., peering agreements, and by technical
specifications or protocols that describe the exchange of data over the
network. Indeed, the Internet is defined by its interconnections and routing
policies.
Services
The Internet carries many network services, most prominently mobile apps such as social media apps, the World Wide Web, electronic mail, multiplayer online games, Internet telephony, and file sharing services.
World
Wide Web
Many people use the terms Internet and World
Wide Web, or just the Web, interchangeably, but the two terms
are not synonymous. The World Wide Web is the primary
application program that billions of people use on the Internet, and it has
changed their lives immeasurably.[56][57] However, the
Internet provides many other services. The Web is a global set of documents, images and other
resources, logically interrelated by hyperlinks and referenced
with Uniform Resource Identifiers (URIs). URIs
symbolically identify services, servers, and other databases,
and the documents and resources that they can provide. Hypertext Transfer Protocol (HTTP) is the main
access protocol of the World Wide Web. Web services also use HTTP to
allow software systems to communicate in order to share and exchange business
logic and data.
World Wide Web browser software, such
as Microsoft's Internet Explorer/Edge, Mozilla Firefox, Opera, Apple's Safari, and Google Chrome, lets users navigate
from one web page to another via hyperlinks embedded in the documents. These
documents may also contain any combination of computer data, including graphics,
sounds, text, video, multimedia and interactive
content that runs while the user is interacting with the page. Client-side software can include
animations, games, office applications and scientific
demonstrations. Through keyword-driven Internet research using search engines like Yahoo!, Bing and Google, users worldwide have
easy, instant access to a vast and diverse amount of online information.
Compared to printed media, books, encyclopedias and traditional libraries, the
World Wide Web has enabled the decentralization of information on a large
scale.
The Web has also enabled individuals and
organizations to publish ideas and
information to a potentially large audience online at greatly
reduced expense and time delay. Publishing a web page, a blog, or building a
website involves little initial cost and many cost-free
services are available. However, publishing and maintaining large, professional
web sites with attractive, diverse and up-to-date information is still a
difficult and expensive proposition. Many individuals and some companies and
groups use web logs or blogs, which are largely used as easily
updatable online diaries. Some commercial organizations encourage staff to communicate
advice in their areas of specialization in the hope that visitors will be
impressed by the expert knowledge and free information, and be attracted to the
corporation as a result.
One example of this practice is Microsoft, whose product developers publish their
personal blogs in order to pique the public's interest in their work.[original research?] Collections of
personal web pages published by large service providers remain popular and have
become increasingly sophisticated. Whereas operations such as Angelfire and GeoCities have existed since
the early days of the Web, newer offerings from, for example, Facebook and Twitter currently have
large followings. These operations often brand themselves as social network services rather than simply
as web page hosts.[citation needed]
Advertising on popular web pages can be
lucrative, and e-commerce, which is the sale of
products and services directly via the Web, continues to grow. Online
advertising is a form of marketing and advertising
which uses the Internet to deliver promotional marketing messages to consumers. It
includes email marketing, search engine marketing (SEM), social media
marketing, many types of display advertising (including web banner advertising),
and mobile advertising. In 2011, Internet advertising
revenues in the United States surpassed those of cable television and nearly exceeded
those of broadcast television.[58]:19 Many common online
advertising practices are controversial and increasingly subject to regulation.
When the Web developed in the 1990s, a
typical web page was stored in completed form on a web server, formatted
in HTML, complete for
transmission to a web browser in response to a request. Over time, the process
of creating and serving web pages has become dynamic, creating a flexible
design, layout, and content. Websites are often created using content management software with, initially,
very little content. Contributors to these systems, who may be paid staff,
members of an organization or the public, fill underlying databases with
content using editing pages designed for that purpose while casual visitors
view and read this content in HTML form. There may or may not be editorial,
approval and security systems built into the process of taking newly entered
content and making it available to the target visitors.
Communication
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Email is an important
communications service available on the Internet. The concept of sending
electronic text messages between parties in a way analogous to mailing letters
or memos predates the creation of the Internet. Pictures, documents, and other
files are sent as email attachments. Emails can be cc-ed to multiple email addresses.
Internet telephony is another common
communications service made possible by the creation of the Internet. VoIP stands for
Voice-over-Internet Protocol, referring to the
protocol that underlies all Internet communication. The idea began in the early
1990s with walkie-talkie-like voice applications
for personal computers. In recent years many VoIP systems have become as easy
to use and as convenient as a normal telephone. The benefit is that, as the
Internet carries the voice traffic, VoIP can be free or cost much less than a
traditional telephone call, especially over long distances and especially for
those with always-on Internet connections such as cable or ADSL. VoIP is maturing into a
competitive alternative to traditional telephone service. Interoperability
between different providers has improved and the ability to call or receive a
call from a traditional telephone is available. Simple, inexpensive VoIP
network adapters are available that eliminate the need for a personal computer.
Voice quality can still vary from call to
call, but is often equal to and can even exceed that of traditional calls.
Remaining problems for VoIP include emergency telephone numberdialing and reliability.
Currently, a few VoIP providers provide an emergency service, but it is not
universally available. Older traditional phones with no "extra
features" may be line-powered only and operate during a power failure;
VoIP can never do so without a backup power source for the phone
equipment and the Internet access devices. VoIP has also become increasingly
popular for gaming applications, as a form of communication between players.
Popular VoIP clients for gaming include Ventrilo and Teamspeak. Modern video game
consoles also offer VoIP chat features.
Data
transfer
File sharing is an example of
transferring large amounts of data across the Internet. A computer file can be emailed to
customers, colleagues and friends as an attachment. It can be uploaded to a
website or File Transfer Protocol (FTP) server for
easy download by others. It can be put into a "shared location" or
onto a file
server for
instant use by colleagues. The load of bulk downloads to many users can be
eased by the use of "mirror" servers or peer-to-peer networks. In any of
these cases, access to the file may be controlled by user authentication, the transit of the file
over the Internet may be obscured by encryption, and money may change
hands for access to the file. The price can be paid by the remote charging of
funds from, for example, a credit card whose details are also passed – usually
fully encrypted – across the Internet. The origin and authenticity of the
file received may be checked by digital signatures or by MD5 or other message
digests. These simple features of the Internet, over a worldwide basis, are
changing the production, sale, and distribution of anything that can be reduced
to a computer file for transmission. This includes all manner of print
publications, software products, news, music, film, video, photography,
graphics and the other arts. This in turn has caused seismic shifts in each of
the existing industries that previously controlled the production and
distribution of these products.
Streaming media is the real-time
delivery of digital media for the immediate consumption or enjoyment by end
users. Many radio and television broadcasters provide Internet feeds of their
live audio and video productions. They may also allow time-shift viewing or
listening such as Preview, Classic Clips and Listen Again features. These
providers have been joined by a range of pure Internet "broadcasters"
who never had on-air licenses. This means that an Internet-connected device,
such as a computer or something more specific, can be used to access on-line
media in much the same way as was previously possible only with a television or
radio receiver. The range of available types of content is much wider, from
specialized technical webcasts to on-demand
popular multimedia services. Podcasting is a variation on
this theme, where – usually audio – material is downloaded and played
back on a computer or shifted to a portable media player to be listened to
on the move. These techniques using simple equipment allow anybody, with little
censorship or licensing control, to broadcast audio-visual material worldwide.
Digital media streaming increases the
demand for network bandwidth. For example, standard image quality needs 1
Mbit/s link speed for SD 480p, HD 720p quality requires 2.5 Mbit/s, and the
top-of-the-line HDX quality needs 4.5 Mbit/s for 1080p.[59]
Webcams are a low-cost
extension of this phenomenon. While some webcams can give full-frame-rate
video, the picture either is usually small or updates slowly. Internet users
can watch animals around an African waterhole, ships in the Panama Canal, traffic at a local
roundabout or monitor their own premises, live and in real time. Video chat rooms and video conferencing are also popular
with many uses being found for personal webcams, with and without two-way sound.
YouTube was founded on 15 February 2005 and is now the leading website for free
streaming video with a vast number of users. It uses a flash-based web player to
stream and show video files. Registered users may upload an unlimited amount of
video and build their own personal profile. YouTube claims that its
users watch hundreds of millions, and upload hundreds of thousands of videos
daily. Currently, YouTube also uses an HTML5 player.[60]
Social impact
The Internet has enabled new forms of
social interaction, activities, and social associations. This phenomenon has
given rise to the scholarly study of the sociology of the Internet.
Users
Internet users per 100
inhabitants
Internet usage has seen tremendous growth.
From 2000 to 2009, the number of Internet users globally rose from 394 million
to 1.858 billion.[65] By 2010, 22 percent
of the world's population had access to computers with 1 billion Google searches every day,
300 million Internet users reading blogs, and 2 billion videos viewed daily
on YouTube.[66] In 2014 the world's
Internet users surpassed 3 billion or 43.6 percent of world population, but
two-thirds of the users came from richest countries, with 78.0 percent of
Europe countries population using the Internet, followed by 57.4 percent of the
Americas.[67]
The prevalent language for communication on
the Internet has been English. This may be a result of the origin of the
Internet, as well as the language's role as a lingua franca. Early computer systems
were limited to the characters in the American Standard Code
for Information Interchange (ASCII), a subset of the Latin alphabet.
After English (27%), the most requested
languages on the World Wide Web are Chinese (25%),
Spanish (8%), Japanese (5%), Portuguese and German (4% each), Arabic, French
and Russian (3% each), and Korean (2%).[63] By region, 42% of
the world's Internet
users are
based in Asia, 24% in Europe, 14% in North America, 10% in Latin America and
the Caribbean taken together, 6%
in Africa, 3% in the Middle East and 1% in Australia/Oceania.[68] The Internet's
technologies have developed enough in recent years, especially in the use
of Unicode, that good facilities
are available for development and communication in the world's widely used
languages. However, some glitches such as mojibake (incorrect display
of some languages' characters) still remain.
In an American study in 2005, the
percentage of men using the Internet was very slightly ahead of the percentage
of women, although this difference reversed in those under 30. Men logged on
more often, spent more time online, and were more likely to be broadband users,
whereas women tended to make more use of opportunities to communicate (such as
email). Men were more likely to use the Internet to pay bills, participate in
auctions, and for recreation such as downloading music and videos. Men and
women were equally likely to use the Internet for shopping and banking.[69] More recent studies
indicate that in 2008, women significantly outnumbered men on most social
networking sites, such as Facebook and Myspace, although the ratios varied with
age.[70] In addition, women
watched more streaming content, whereas men downloaded more.[71] In terms of blogs,
men were more likely to blog in the first place; among those who blog, men were
more likely to have a professional blog, whereas women were more likely to have
a personal blog.[72]
According to forecasts by Euromonitor International, 44% of the world's
population will be users of the Internet by 2020.[73] Splitting by
country, in 2012 Iceland, Norway, Sweden, the Netherlands, and Denmark had the
highest Internet penetration by
the number of users, with 93% or more of the population with access.[74]
Several neologisms exist that refer to
Internet users: Netizen (as in as in
"citizen of the net")[75] refers to
those actively involved in improving online communities, the Internet in general
or surrounding political affairs and rights such as free speech,[76][77] Internaut refers to operators
or technically highly capable users of the Internet,[78][79] digital citizen refers to a person
using the Internet in order to engage in society, politics, and government
participation.[80]
Usage
The Internet allows greater flexibility in
working hours and location, especially with the spread of unmetered high-speed
connections. The Internet can be accessed almost anywhere by numerous means,
including through mobile Internet devices. Mobile phones, datacards, handheld game consoles and cellular routers allow users to
connect to the Internet wirelessly. Within the limitations
imposed by small screens and other limited facilities of such pocket-sized
devices, the services of the Internet, including email and the web, may be
available. Service providers may restrict the services offered and mobile data charges
may be significantly higher than other access methods.
Educational material at all levels from
pre-school to post-doctoral is available from websites. Examples range
from CBeebies, through school and
high-school revision guides and virtual universities, to access to top-end
scholarly literature through the likes of Google Scholar. For distance education, help with homework and other
assignments, self-guided learning, whiling away spare time, or just looking up
more detail on an interesting fact, it has never been easier for people to
access educational information at any level from anywhere. The Internet in general
and the World
Wide Web in
particular are important enablers of both formal and informal education. Further, the Internet
allows universities, in particular, researchers from the social and behavioral
sciences, to conduct research remotely via virtual laboratories, with profound
changes in reach and generalizability of findings as well as in communication
between scientists and in the publication of results.[81]
The low cost and nearly instantaneous
sharing of ideas, knowledge, and skills have made collaborative work dramatically
easier, with the help of collaborative software. Not only can a group
cheaply communicate and share ideas but the wide reach of the Internet allows
such groups more easily to form. An example of this is the free software movement, which has produced,
among other things, Linux, Mozilla Firefox, and OpenOffice.org (later forked
into LibreOffice). Internet chat, whether
using an IRC chat room, an instant messagingsystem, or a social networking website, allows
colleagues to stay in touch in a very convenient way while working at their
computers during the day. Messages can be exchanged even more quickly and
conveniently than via email. These systems may allow files to be exchanged,
drawings and images to be shared, or voice and video contact between team
members.
Content management systems allow collaborating
teams to work on shared sets of documents simultaneously without accidentally
destroying each other's work. Business and project teams can share calendars as
well as documents and other information. Such collaboration occurs in a wide
variety of areas including scientific research, software development,
conference planning, political activism and creative writing. Social and
political collaboration is also becoming more widespread as both Internet
access and computer literacy spread.
The Internet allows computer users to
remotely access other computers and information stores easily from any access
point. Access may be with computer security, i.e. authentication and
encryption technologies, depending on the requirements. This is encouraging new
ways of working from home, collaboration and information sharing in many
industries. An accountant sitting at home can audit the books of a
company based in another country, on a server situated in a third country that is
remotely maintained by IT specialists in a fourth. These accounts could have
been created by home-working bookkeepers, in other remote locations, based on
information emailed to them from offices all over the world. Some of these
things were possible before the widespread use of the Internet, but the cost of
private leased
lines would
have made many of them infeasible in practice. An office worker away from their
desk, perhaps on the other side of the world on a business trip or a holiday,
can access their emails, access their data using cloud computing, or open a remote desktop session into their
office PC using a secure virtual private network (VPN) connection on
the Internet. This can give the worker complete access to all of their normal
files and data, including email and other applications, while away from the
office. It has been referred to among system administrators as the Virtual
Private Nightmare,[82] because it extends
the secure perimeter of a corporate network into remote locations and its
employees' homes.
Social
networking and entertainment
Many people use the World Wide Web to
access news, weather and sports reports, to plan and book vacations and to
pursue their personal interests. People use chat, messaging and email to
make and stay in touch with friends worldwide, sometimes in the same way as
some previously had pen
pals. Social networking websites such
as Facebook, Twitter, and Myspace have created new
ways to socialize and interact. Users of these sites are able to add a wide
variety of information to pages, to pursue common interests, and to connect
with others. It is also possible to find existing acquaintances, to allow
communication among existing groups of people. Sites like LinkedIn foster commercial
and business connections. YouTube and Flickr specialize in
users' videos and photographs. While social networking sites were initially for
individuals only, today they are widely used by businesses and other
organizations to promote their brands, to market to their customers and to
encourage posts to "go viral". "Black
hat" social media techniques are also employed by some organizations, such
as spam accounts and astroturfing.
A risk for both individuals and
organizations writing posts (especially public posts) on social networking websites,
is that especially foolish or controversial posts occasionally lead to an
unexpected and possibly large-scale backlash on social media from other
Internet users. This is also a risk in relation to controversial offline behavior,
if it is widely made known. The nature of this backlash can range widely from
counter-arguments and public mockery, through insults and hate speech, to, in extreme cases,
rape and death threats. The online disinhibition effect describes the
tendency of many individuals to behave more stridently or offensively online
than they would in person. A significant number of feminist women have been the
target of various forms of harassment in response to
posts they have made on social media, and Twitter in particular has been
criticised in the past for not doing enough to aid victims of online abuse.[83]
For organizations, such a backlash can
cause overall brand damage, especially if reported
by the media. However, this is not always the case, as any brand damage in the
eyes of people with an opposing opinion to that presented by the organization
could sometimes be outweighed by strengthening the brand in the eyes of others.
Furthermore, if an organization or individual gives in to demands that others
perceive as wrong-headed, that can then provoke a counter-backlash.
Some websites, such as Reddit, have rules forbidding
the posting of personal information of individuals
(also known as doxxing), due to concerns about
such postings leading to mobs of large numbers of Internet users directing
harassment at the specific individuals thereby identified. In particular, the
Reddit rule forbidding the posting of personal information is widely understood
to imply that all identifying photos and names must be censored in Facebook screenshots posted to Reddit.
However, the interpretation of this rule in relation to public Twitter posts is
less clear, and in any case, like-minded people online have many other ways
they can use to direct each other's attention to public social media posts they
disagree with.
Children also face dangers online such
as cyberbullying and approaches by sexual
predators,
who sometimes pose as children themselves. Children may also encounter material
which they may find upsetting, or material which their parents consider to be
not age-appropriate. Due to naivety, they may also post personal information
about themselves online, which could put them or their families at risk unless
warned not to do so. Many parents choose to enable Internet filtering, and/or supervise their
children's online activities, in an attempt to protect their children from
inappropriate material on the Internet. The most popular social networking
websites, such as Facebook and Twitter, commonly forbid users under the age of
13. However, these policies are typically trivial to circumvent by registering
an account with a false birth date, and a significant number of children aged
under 13 join such sites anyway. Social networking sites for younger children,
which claim to provide better levels of protection for children, also exist.[84]
The Internet has been a major outlet for
leisure activity since its inception, with entertaining social experiments such as MUDs and MOOs being conducted on
university servers, and humor-related Usenet groups receiving
much traffic.[citation needed] Many Internet forums have sections
devoted to games and funny videos.[citation needed] The Internet pornographyand online gambling industries have
taken advantage of the World Wide Web, and often provide a significant source
of advertising revenue for other websites.[85] Although many
governments have attempted to restrict both industries' use of the Internet, in
general, this has failed to stop their widespread popularity.[86]
Another area of leisure activity on the
Internet is multiplayer gaming.[87] This form of
recreation creates communities, where people of all ages and origins enjoy the
fast-paced world of multiplayer games. These range from MMORPG to first-person shooters, from role-playing video games to online gambling. While online gaming has
been around since the 1970s, modern modes of online gaming began with
subscription services such as GameSpy and MPlayer.[88] Non-subscribers
were limited to certain types of game play or certain games. Many people use
the Internet to access and download music, movies and other works for their
enjoyment and relaxation. Free and fee-based services exist for all of these
activities, using centralized servers and distributed peer-to-peer
technologies. Some of these sources exercise more care with respect to the
original artists' copyrights than others.
Internet usage has been correlated to
users' loneliness.[89] Lonely people tend
to use the Internet as an outlet for their feelings and to share their stories
with others, such as in the "I am lonely will anyone speak to me" thread.
Cybersectarianism is a new
organizational form which involves: "highly dispersed small groups of
practitioners that may remain largely anonymous within the larger social context
and operate in relative secrecy, while still linked remotely to a larger
network of believers who share a set of practices and texts, and often a common
devotion to a particular leader. Overseas supporters provide funding and
support; domestic practitioners distribute tracts, participate in acts of
resistance, and share information on the internal situation with outsiders.
Collectively, members and practitioners of such sects construct viable virtual
communities of faith, exchanging personal testimonies and engaging in the
collective study via email, on-line chat rooms, and web-based message
boards."[90] In particular, the
British government has raised concerns about the prospect of young British
Muslims being indoctrinated into Islamic extremism by material on the Internet,
being persuaded to join terrorist groups such as the
so-called "Islamic State", and then
potentially committing acts of terrorism on returning to Britain after fighting
in Syria or Iraq.
Cyberslacking can become a drain
on corporate resources; the average UK employee spent 57 minutes a day surfing
the Web while at work, according to a 2003 study by Peninsula Business
Services.[91] Internet addiction disorder is excessive
computer use that interferes with daily life. Nicholas G. Carr believes that
Internet use has other effects on individuals, for instance improving
skills of scan-reading and interfering with the deep thinking that leads to
true creativity.[92]
Electronic
business
Electronic business (e-business)
encompasses business processes spanning the entire value chain: purchasing, supply chain management, marketing, sales, customer service, and
business relationship. E-commerce seeks to add
revenue streams using the Internet to build and enhance relationships with
clients and partners. According to International Data Corporation, the size of worldwide
e-commerce, when global business-to-business and -consumer transactions are
combined, equate to $16 trillion for 2013. A report by Oxford Economics adds
those two together to estimate the total size of the digital economy at $20.4 trillion,
equivalent to roughly 13.8% of global sales.[93]
While much has been written of the economic
advantages of Internet-enabled commerce, there is also evidence
that some aspects of the Internet such as maps and location-aware services may
serve to reinforce economic inequality and the digital divide.[94] Electronic commerce
may be responsible for consolidation and the decline
of mom-and-pop, brick and mortar businesses
resulting in increases in income inequality.[95][96][97]
Author Andrew Keen, a long-time critic of
the social transformations caused by the Internet, has recently focused on the
economic effects of consolidation from Internet businesses. Keen cites a
2013 Institute for Local Self-Reliance report saying
brick-and-mortar retailers employ 47 people for every $10 million in sales
while Amazon employs only 14. Similarly, the 700-employee room rental
start-up Airbnb was valued at $10
billion in 2014, about half as much as Hilton Hotels, which employs 152,000
people. And car-sharing Internet startup Uber employs 1,000
full-time employees and is valued at $18.2 billion, about the same valuation
as Avis and Hertz combined, which together employ
almost 60,000 people.[98]
Telecommuting
Telecommuting is the performance
within a traditional worker and employer relationship when it is facilitated by
tools such as groupware, virtual private networks, conference calling, videoconferencing, and voice over IP (VOIP) so that work
may be performed from any location, most conveniently the worker's home. It can
be efficient and useful for companies as it allows workers to communicate over
long distances, saving significant amounts of travel time and cost. As broadband Internet
connections become commonplace, more workers have adequate bandwidth at home to
use these tools to link their home to their corporate intranet and internal
communication networks.
Collaborative
publishing
Wikis have also been used
in the academic community for sharing and dissemination of information across
institutional and international boundaries.[99] In those settings,
they have been found useful for collaboration on grant writing, strategic planning, departmental documentation,
and committee work.[100] The United States Patent and
Trademark Office uses a wiki to allow the public to collaborate on
finding prior
art relevant
to examination of pending patent applications. Queens, New York has used a
wiki to allow citizens to collaborate on the design and planning of a local
park.[101] The English Wikipedia has the largest
user base among wikis on the World Wide Web[102] and ranks in the
top 10 among all Web sites in terms of traffic.[103]
Politics
and political revolutions
Banner in Bangkok during the 2014 Thai coup d'état, informing the Thaipublic that 'like' or
'share' activities on social media could result in imprisonment (observed June
30, 2014).
The Internet has achieved new relevance as
a political tool. The presidential campaign of Howard Dean in 2004 in the
United States was notable for its success in soliciting donation via the
Internet. Many political groups use the Internet to achieve a new method of
organizing for carrying out their mission, having given rise to Internet activism, most notably practiced
by rebels in the Arab
Spring.[104][105] The New York Times suggested
that social
media websites,
such as Facebook and Twitter, helped people organize the political revolutions
in Egypt, by helping activists organize protests, communicate grievances, and
disseminate information.[106]
The potential of the Internet as a civic
tool of communicative power was explored by Simon R. B. Berdal in his 2004
thesis:
As the globally evolving Internet provides
ever new access points to virtual discourse forums, it also promotes new civic
relations and associations within which communicative power may flow and
accumulate. Thus, traditionally … national-embedded peripheries get entangled
into greater, international peripheries, with stronger combined powers... The
Internet, as a consequence, changes the topology of the "centre-periphery"
model, by stimulating conventional peripheries to interlink into
"super-periphery" structures, which enclose and "besiege"
several centres at once.[107]
Berdal, therefore, extends the Habermasian notion of the public sphere to the Internet,
and underlines the inherent global and civic nature that interwoven Internet
technologies provide. To limit the growing civic potential of the Internet,
Berdal also notes how "self-protective measures" are put in place by
those threatened by it:
If we consider China’s attempts to filter
"unsuitable material" from the Internet, most of us would agree that
this resembles a self-protective measure by the system against the growing
civic potentials of the Internet. Nevertheless, both types represent limitations
to "peripheral capacities". Thus, the Chinese government tries to
prevent communicative power to build up and unleash (as the 1989 Tiananmen Square uprising suggests, the
government may find it wise to install "upstream measures"). Even
though limited, the Internet is proving to be an empowering tool also to the
Chinese periphery: Analysts believe that Internet petitions have influenced
policy implementation in favour of the public’s online-articulated will …[107]
Incidents of politically motivated Internet censorship have now been
recorded in many countries, including western democracies.
Philanthropy
The spread of low-cost Internet access in
developing countries has opened up new possibilities for peer-to-peer charities, which
allow individuals to contribute small amounts to charitable projects for other
individuals. Websites, such as DonorsChoose and GlobalGiving, allow small-scale
donors to direct funds to individual projects of their choice. A popular twist
on Internet-based philanthropy is the use of peer-to-peer lending for charitable
purposes. Kiva pioneered this concept in 2005,
offering the first web-based service to publish individual loan profiles for
funding. Kiva raises funds for local intermediary microfinance organizations which
post stories and updates on behalf of the borrowers. Lenders can contribute as
little as $25 to loans of their choice, and receive their money back as
borrowers repay. Kiva falls short of being a pure peer-to-peer charity, in that
loans are disbursed before being funded by lenders and borrowers do not
communicate with lenders themselves.[108][109]
However, the recent spread of low-cost
Internet access in developing countries has made genuine
international person-to-person philanthropy increasingly feasible. In 2009, the
US-based nonprofit Zidisha tapped into this
trend to offer the first person-to-person microfinance platform to link lenders
and borrowers across international borders without intermediaries. Members can
fund loans for as little as a dollar, which the borrowers then use to develop
business activities that improve their families' incomes while repaying loans
to the members with interest. Borrowers access the Internet via public
cybercafes, donated laptops in village schools, and even smart phones, then
create their own profile pages through which they share photos and information
about themselves and their businesses. As they repay their loans, borrowers
continue to share updates and dialogue with lenders via their profile pages.
This direct web-based connection allows members themselves to take on many of
the communication and recording tasks traditionally performed by local
organizations, bypassing geographic barriers and dramatically reducing the cost
of microfinance services to the entrepreneurs.[110]
Security
Internet resources, hardware, and software
components are the target of criminal or malicious attempts to gain
unauthorized control to cause interruptions, commit fraud, engage in blackmail
or access private information.
Malware
Malicious software used and spread on the
Internet includes computer viruses which copy with the
help of humans, computer worms which copy
themselves automatically, software for denial of service attacks, ransomware, botnets, and spyware that reports on the
activity and typing of users. Usually, these activities constitute cybercrime. Defense theorists have
also speculated about the possibilities of cyber warfare using similar
methods on a large scale.[citation needed]
Surveillance
The vast majority of computer surveillance
involves the monitoring of data and traffic on the Internet.[111] In the United
States for example, under the Communications Assistance
For Law Enforcement Act, all phone calls and broadband Internet
traffic (emails, web traffic, instant messaging, etc.) are required to be
available for unimpeded real-time monitoring by Federal law enforcement
agencies.[112][113][114] Packet capture is the monitoring
of data traffic on a computer network. Computers communicate
over the Internet by breaking up messages (emails, images, videos, web pages,
files, etc.) into small chunks called "packets", which are routed
through a network of computers, until they reach their destination, where they
are assembled back into a complete "message" again. Packet Capture Appliance intercepts these
packets as they are traveling through the network, in order to examine their
contents using other programs. A packet capture is an information gathering tool,
but not an analysis tool. That is it gathers
"messages" but it does not analyze them and figure out what they
mean. Other programs are needed to perform traffic analysis and sift through
intercepted data looking for important/useful information. Under the Communications Assistance
For Law Enforcement Act all U.S. telecommunications providers
are required to install packet sniffing technology to allow Federal law
enforcement and intelligence agencies to intercept all of their
customers' broadband Internet and voice over Internet protocol (VoIP) traffic.[115]
The large amount of data gathered from
packet capturing requires surveillance software that filters and reports
relevant information, such as the use of certain words or phrases, the access
of certain types of web sites, or communicating via email or chat with certain
parties.[116] Agencies, such as
the Information Awareness Office, NSA, GCHQ and the FBI, spend billions of
dollars per year to develop, purchase, implement, and operate systems for
interception and analysis of data.[117] Similar systems are
operated by Iranian secret police to identify and
suppress dissidents. The required hardware and software was allegedly installed
by German Siemens
AG and
Finnish Nokia.[118]