Internet
The Internet is a global system of interconnected computer
networks that use
the standard Internet protocol suite (TCP/IP) to serve several billion
users worldwide. It is anetwork of networks that consists of millions of private,
public, academic, business, and government networks, of local to global scope,
that are linked by a broad array of electronic, wireless and optical networking
technologies. The Internet carries an extensive range of information resources
and services, such as the inter-linked hypertext documents of the World
Wide Web (WWW),
the infrastructure to support email, and peer-to-peernetworks.
Most traditional communications
media including telephone, music, film, and television are being reshaped or
redefined by the Internet, giving birth to new services such as voice over Internet Protocol (VoIP) and Internet Protocol television (IPTV). Newspaper, book and other print
publishing are adapting to website technology, or are reshaped into blogging and web
feeds. The Internet has enabled and accelerated new forms of human interactions
throughinstant messaging, Internet forums, and social networking. Online
shopping has
boomed both for major retail outlets and small artisans and traders. Business-to-business andfinancial services on the
Internet affect supply
chains across
entire industries.
The origins of the Internet reach
back to research commissioned by the United States government in the 1960s to build robust, fault-tolerant
communication via computer networks. While this work together with work in the
United Kingdom and France lead to important precursor networks, they were not
the Internet. There is no consensus on the exact date when the modern Internet
came into being, but sometime in the early to mid-1980s is considered
reasonable.
The funding of a new U.S. backbone by the National Science Foundation in the 1980s, as well as private funding for
other commercial backbones, led to worldwide participation in the development
of new networking technologies, and the merger of many networks. Though the
Internet has been widely used by academia since the 1980s, thecommercialization of what was by the 1990s an international
network resulted in its popularization and incorporation into virtually every
aspect of modern human life. As of June 2012, more than 2.4 billion people—over
a third of the world's
human population—have used the services of the Internet; approximately 100 times
more people than were using it in 1995.[1][2]
The Internet has no centralized
governance in either technological implementation or policies for access and
usage; each constituent network sets its own policies. Only the overreaching
definitions of the two principal name
spaces in the
Internet, the Internet
Protocol address space and
the Domain Name System, are directed by a maintainer
organization, the Internet
Corporation for Assigned Names and Numbers (ICANN). 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.
Terminology
The Internet, referring to the
specific global system of interconnected IP networks, is aproper
noun and
written with an initial capital
letter. In the media and common use it is often 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 a
verb or an adjective.[3] The Internet is also often referred to as the Net.
Historically the word internet was used, uncapitalized, as early as
1883 as a verb and adjective to refer to interconnected motions. Starting in
the early 1970s the terminternet was
used as a shorthand form of the technical term internetwork, the
result of interconnecting computer networks with special gateways or routers.
It was also used as a verb meaning to connect together, especially for
networks.[4][5]
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 invoking a web
browserto view web
pages. However, the Internet is a particular global computer network
connecting millions of computing devices; the World
Wide Web is just
one of many services running on the Internet. The Web is a
collection of interconnected documents (web pages) and other web
resources, linked by hyperlinks and URLs.[6] In addition to the Web, a multitude of other
services are implemented over the Internet, including e-mail, file
transfer, remote computer control, newsgroups, and online
games. Web (and other) services can be implemented on any intranet,
accessible to network users.
Interweb is a mixture of Internet and World
Wide Web typically used
sarcastically to parody a technically unsavvy user.[7]
History
Research into packet
switching started
in the early 1960s and packet switched networks such as Mark I at NPL in the UK,[8] ARPANET, CYCLADES,[9][10] Merit
Network,[11] Tymnet, and Telenet, were developed in the late 1960s and
early 1970s using a variety of protocols. The ARPANET in particular led to the
development of protocols for internetworking, where
multiple separate networks could be joined together into a network of networks.[citation needed]
The first two nodes of what would
become the ARPANET were interconnected between Leonard
Kleinrock's Network Measurement Center at the UCLA's
School of Engineering and Applied Scienceand Douglas
Engelbart's NLS
system at SRI
International (SRI) in Menlo Park, California, on 29 October 1969.[12] The third site on the ARPANET was the
Culler-Fried Interactive Mathematics center at the University of California at
Santa Barbara, and the fourth was the University of Utah Graphics
Department. In an early sign of future growth, there were already fifteen sites
connected to the young ARPANET by the end of 1971.[13][14] These early years were documented in the 1972
film Computer
Networks: The Heralds of Resource Sharing.
Early international
collaborations on ARPANET were sparse. For various political reasons, European
developers were concerned with developing the X.25 networks.[15] Notable exceptions were the Norwegian Seismic Array (NORSAR) in June
1973,[16] followed in 1973 by Sweden with satellite
links to the Tanum Earth Station and Peter
T. Kirstein's research group in the UK, initially at the Institute of Computer Science, University of London and later at University College London.[citation needed]
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 repeat
this use.[17] Access to the ARPANET was expanded in 1981
when the National Science Foundation (NSF) developed the Computer Science Network (CSNET). In 1982, theInternet Protocol Suite (TCP/IP) was standardized and the concept of
a world-wide network of fully interconnected TCP/IP networks called the
Internet was introduced.
TCP/IP network access expanded again in 1986
when the National Science Foundation Network (NSFNET) provided access to supercomputer sites in the United States
from research and education organizations, first at 56 kbit/s and later at 1.5
Mbit/s and 45 Mbit/s.[18] Commercial Internet
service providers(ISPs)
began to emerge in the late 1980s and early 1990s. The ARPANET was
decommissioned in 1990. The Internet was commercialized in 1995 when NSFNET was
decommissioned, removing the last restrictions on the use of the Internet to
carry commercial traffic.[19] The Internet started a
rapid expansion to Europe and Australia in the mid to late 1980s[20][21] and to Asia in the late
1980s and early 1990s.[22]
Since the mid-1990s the Internet has had a
tremendous impact on culture and commerce, including the rise of near instant
communication by email, instant messaging, Voice
over Internet Protocol (VoIP) "phone calls", two-way interactive video calls, and the World Wide Web[23] 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
|
2013a
|
|
6.5 billion
|
6.9 billion
|
7.1 billion
|
|
|
Not using the Internet
|
84%
|
70%
|
61%
|
|
Using the Internet
|
16%
|
30%
|
39%
|
|
Users in the developing
world
|
8%
|
21%
|
31%
|
|
Users in the developed
world
|
51%
|
67%
|
77%
|
The Internet continues to grow, driven by
ever greater amounts of online information and knowledge, commerce,
entertainment and social networking.[26] 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%.[27] This growth is often
attributed to the lack of central administration, which allows organic growth
of the network, as well as the non-proprietary open nature of the Internet
protocols, which encourages vendor interoperability and prevents any one
company from exerting too much control over the network.[28] As of 31 March 2011, the
estimated total number of Internet users was 2.095 billion
(30.2% of world population).[29] 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.[30]
Technology
Protocols
The communications infrastructure
of the Internet consists of its hardware components and a system of software
layers that control various aspects of the architecture. While the hardware can
often be used to support other software systems, it is the design and the
rigorous standardization process of the software architecture 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 delegated to the Internet Engineering Task Force (IETF).[31] The IETF conducts standard-setting work
groups, open to any individual, about the various aspects of Internet
architecture. Resulting discussions and final standards are published in a
series of publications, each called a Request for Comments (RFC), freely available 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 (RFC 1122,RFC 1123).
The layers correspond to the environment or scope in which their services
operate. At the top is the application
layer, the space for the application-specific networking methods used
in software applications, e.g., a web browser program uses theclient-server application model and many file-sharing
systems use a peer-to-peerparadigm.
Below this top layer, the transport
layer connects
applications on different
hostsvia the network with appropriate data exchange methods. Underlying
these layers are the core networking technologies, consisting of two layers.
The internet
layer enables
computers to identify and locate each other via Internet
Protocol (IP) addresses, and allows them to connect to one another
via intermediate (transit) networks. Last, at the bottom of the architecture,
is a software layer, the link
layer, that provides connectivity between hosts on the same local
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, which the model
therefore does not concern itself with in any detail. Other models have been
developed, such as the Open Systems Interconnection (OSI) model, but they are not compatible in
the details of description or implementation; many similarities exist and the
TCP/IP protocols are usually included in the discussion of OSI networking.
The most prominent component of
the Internet model is the Internet Protocol (IP), which provides addressing
systems (IP addresses) for computers on the Internet. IP enables
internetworking and in essence establishes the Internet itself. IP Version 4 (IPv4) is the
initial version used on the first generation of today's Internet and is still
in dominant use. It was designed to address up to ~4.3 billion (109)
Internet hosts. However, the explosive growth of the Internet has led to IPv4 address exhaustion, which entered its final stage
in 2011,[32] 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.[33]
IPv6 is not interoperable with
IPv4. In essence, it establishes a parallel version of the Internet not
directly accessible with IPv4 software. This means software upgrades or
translator facilities are necessary for networking devices that need to
communicate on both networks. Most modern computer operating systems already
support both versions of the Internet Protocol. Network infrastructures, however,
are still 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 how
to exchange data over the network. Indeed, the Internet is defined by its
interconnections and routing policies.
Routing
Internet service providers connect customers, which represent the bottom
of the routing hierarchy, to customers of other ISPs via other higher or
same-tier networks. At the top of the routing hierarchy are the Tier 1
networks, large telecommunication companies which exchange traffic
directly with all other Tier 1 networks via peering agreements. Tier 2
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. Internet exchange points are major traffic exchanges with physical
connections to multiple ISPs.
Computers and routers use routing
tables to direct
IP packets to the next-hop router or destination. Routing tables are maintained
by manual configuration or 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.
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 into large
subnetworks such as GEANT, GLORIAD, Internet2, and the
UK's national research and education
network, JANET.
General
structure
The Internet structure and its
usage characteristics have been studied extensively. It has been determined
that both the Internet IP routing structure and hypertext links of the World
Wide Web are examples of scale-free networks.[34]
Many computer scientists describe
the Internet as a "prime example of a large-scale, highly engineered, yet
highly complex system".[35] The Internet is heterogeneous; for instance, data
transfer rates and
physical characteristics of connections vary widely. The Internet exhibits
"emergent
phenomena" that depend on its large-scale organization. For example,
data transfer rates exhibit temporal self-similarity. The
principles of the routing and addressing methods for traffic in the Internet
reach back to their origins in the 1960s when the eventual scale and popularity
of the network could not be anticipated.[36] Thus, the possibility of developing
alternative structures is investigated.[37] The Internet structure was found to be highly
robust[38] to
random failures and very vulnerable to high degree attacks.[39]
Governance
The Internet is a globally
distributed network comprising
many voluntarily interconnected autonomous networks. It operates without a
central governing body.
The technical underpinning and
standardization of the Internet's core protocols (IPv4 andIPv6) 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), headquartered inMarina del Rey, California. ICANN
is the authority that 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, in which names and numbers are uniquely assigned, are essential for
maintaining the global reach of the Internet. ICANN is governed by an
international board of directors drawn from across the Internet technical,
business, academic, and other non-commercial communities. ICANN's role in
coordinating the assignment of unique identifiers distinguishes it as perhaps
the only central coordinating body for the global Internet.[40]
·
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, continues to have final approval over changes to the DNS
root zone.[41][42][43]
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".[44] 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, held in Tunis,
established the Internet Governance Forum (IGF) to discuss Internet-related issues.
Modern uses
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.
The low cost and nearly
instantaneous sharing of ideas, knowledge, and skills has 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.
Internet chat, whether using an IRC chat room, an instant
messaging system,
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,
wherever they may be. They may do this with or without 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,[45] because
it extends the secure perimeter of a corporate network into remote locations
and its employees' homes.
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 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, but it is only one of the hundreds of communication protocols
used on the Internet. 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, 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! 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.
Publishing and maintaining large, professional web sites with attractive,
diverse and up-to-date information is still a difficult and expensive
proposition, however. 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.
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 servicesrather than simply as web page
hosts.
Advertising on
popular web pages can be lucrative, and e-commerce or the sale of products and services directly
via the Web continues to grow.
When the Web began in the 1990s,
a typical web page was stored in completed form on a web server, formatted in HTML, ready
to be sent to a user's browser in response to a request. Over time, the process
of creating and serving web pages has become more automated and more dynamic.
Websites are often created using content management or wiki software with, initially, very little
content. Contributors to these systems, who may be paid staff, members of a
club or other organization or members of the public, fill underlying databases
with content using editing pages designed for that purpose, while casual
visitors view and read this content in its final 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
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 orADSL. 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 number dialing 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
includeVentrilo 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 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.[46]
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.[47]
Access
Common methods of Internet
access in homes
include dial-up, landline broadband (over coaxial
cable, fiber
optic or copper
wires), Wi-Fi, satellite and 3G/4G technology cell
phones. Public places to use the Internet include libraries and Internet
cafes, where computers with Internet connections are available. There
are also Internet
access points in many
public places such as airport halls and coffee shops, in some cases just for
brief use while standing. Various terms are used, such as "public Internet
kiosk", "public access terminal", and "Web payphone".
Many hotels now also have public terminals, though these are usually fee-based.
These terminals are widely accessed for various usage like ticket booking, bank
deposit, online payment etc. Wi-Fi provides wireless access to computer
networks, and therefore can do so to the Internet itself. Hotspots providing such access include Wi-Fi
cafes, where would-be users need to bring their own wireless-enabled
devices such as a laptop or PDA. These services may be free to
all, free to customers only, or fee-based. A hotspot need not be limited to a
confined location. A whole campus or park, or even an entire city can be
enabled.
Grassroots efforts have led to wireless community networks.
Commercial Wi-Fi services covering large city areas are in place in London, Vienna, Toronto, San
Francisco, Philadelphia, Chicago
and Pittsburgh. The
Internet can then be accessed from such places as a park bench.[48] 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.[49] An Internet access provider and protocol
matrix differentiates the methods used to get online.
An Internet blackout or outage
can be caused by local signaling interruptions. Disruptions of submarine communications cables may cause blackouts or slowdowns to large
areas, such as in the 2008 submarine cable disruption.
Less-developed countries are more vulnerable due to a small number of
high-capacity links. Land cables are also vulnerable, as in 2011 when a woman
digging for scrap metal severed most connectivity for the nation of Armenia. Internet blackouts affecting almost
entire countries can be achieved by governments as a form of Internet censorship, as in the
blockage of the Internet in Egypt,
whereby approximately 93% of
networks were without access in 2011 in an attempt to stop mobilization for anti-government protests.
Users
Overall Internet usage has seen
tremendous growth. From 2000 to 2009, the number of Internet users globally
rose from 394 million to 1.858 billion. 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.
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 (23%),
Spanish (8%), Japanese (5%), Portuguese and German (4% each), Arabic, French
and Russian (3% each), and Korean (2%). By
region, 42% of the world’s Internet 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. 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. 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. In addition,
women watched more streaming content, whereas men downloaded more. 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.
According to Euro monitor, by
2020 43.7% of the world's population will be users of the Internet. Splitting
by country, in 2011 Iceland, Norway and the Netherlands had the highest
Internet penetration by the number of users, with more than 90% of the
population with access.
Social impact
The Internet has enabled entirely
new forms of social interaction, activities, and organizing, thanks to its
basic features such as widespread usability and access. In the first decade of
the 21st century, the first generation is raised with widespread availability
of Internet connectivity, bringing consequences and concerns in areas such as
personal privacy and identity, and distribution of copyrighted materials. These
"digital natives" face a variety of challenges that were not present
for prior generations.
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 find out more about their 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. The
Internet has seen a growing number of Web
desktops, where users can access their files and settings via the Internet.
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.
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. Today,
many Internetforums have sections
devoted to games and funny videos; short cartoons in the form of Flash movies are also popular. Over 6 million
people use blogs or message boards as a means of communication and for the
sharing of ideas. The Internet
pornography and gambling industries have taken
advantage of the World Wide Web, and often provide a significant source of
advertising revenue for other websites. Although
many governments have attempted to restrict both industries' use of the
Internet, in general this has failed to stop their widespread popularity.
Another area of leisure activity
on the Internet is multiplayer
gaming. 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 Game
Spy and M Player. 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. 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.
Cyber sectarianism 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 collective study via email, on-line chat
rooms and web-based message boards."
Cyber slacking 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. Internet addiction disorder is excessive computer use that
interferes with daily life. Psychologist Nicolas Carr believe 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.
Electronic
business
Electronic business (E-business)
involves business processes spanning the entire value chain: electronic purchasing and supply chain management, processing
orders electronically, handling customer service, and cooperating with business
partners. E-commerce seeks to add revenue streams using the
Internet to build and enhance relationships with clients and partners.
According to research firm IDC, the size of total worldwide
e-commerce, when global business-to-business and -consumer transactions are
added together, will equate to $16 trillion in 2013. I Date, another research firm,
estimate the global market for digital products and services at $4.4 trillion
in 2013. A report by Oxford
Economics adds those two together
to estimate the total size of the economy
at $20.4 trillion, equivalent to roughly 13.8% of global sales.
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. Electronic commerce may be responsible
for consolidation and the decline of mom-and-pop, brick and mortar businesses resulting in increases inincome
inequality.
Telecommuting
Remote work is facilitated by
tools such as groupware, virtual private networks, conference calling, videoconferencing, and Voice over IP(VOIP). 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 more
commonplace, more and more workers have adequate bandwidth at home to use these
tools to link their home to their corporate intranet and internal phone networks.
Crowdsourcing
Internet provides a particularly
good venue for crowdsourcing (outsourcing tasks
to a distributed group of people) since individuals tend to be more open in
web-based projects where they are not being physically judged or scrutinized
and thus can feel more comfortable sharing.
Crowdsourcing systems are used to
accomplish a variety of tasks. For example, the crowd may be invited to develop
a new technology, carry out a design task, refine or carry out the steps of an
algorithm (see human-based
computation), or help capture, systematize, or analyze large amounts of data
(see also citizen science).
Wikis have also been used in the academic
community for sharing and dissemination of information across institutional and
international boundaries. In those settings, they have been found useful for
collaboration on grant writing, strategic planning, departmental
documentation, and committee work. 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.
The English Wikipedia has the largest user base among wikis on
the World Wide Web and ranks in the top 10 among all Web sites in
terms of traffic.
Politics
and political revolutions
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 in order to carry
out their mission, having given rise to Internet
activism, most notably practiced by rebels in the Arab Spring.
The New York Times suggested that social media websites, such as Facebook and
Twitter, helped people organize the political revolutions in Egypt where it
helped certain classes of protesters organize protests, communicate grievances,
and disseminate information.
The potential of the Internet as
a civic tool of communicative power was thoroughly explored by Simon R. B. Berdal in his thesis of 2004:
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 centers at once.
Berdal, therefore, extends the Habermasian notion
of the Public sphere to the Internet, and underlines the
inherent global and civic nature that intervowen 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 ...[86]
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 Donors Choose and Global
Giving, 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.
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.
Censorship
Some governments, such as those
of Burma, Iran, North Korea, the Mainland China, Saudi Arabia, and the United Arab Emirates restrict what people in their
countries can access on the Internet, especially political and religious
content. This is accomplished through software that filters domains and content
so that they may not be easily accessed or obtained without elaborate circumvention.
In Norway, Denmark, Finland, and
Sweden, major Internet service providers have voluntarily, possibly to avoid
such an arrangement being turned into law, agreed to restrict access to sites
listed by authorities. While this list of forbidden URLs is supposed to contain
addresses of only known child pornography sites, the content of the list is
secret. Many countries, including the United States, have enacted
laws against the possession or distribution of certain material, such as child pornography, via the Internet,
but do not mandate filtering software. There are many free and commercially
available software programs, called content-control
software, with which a user can choose to block offensive websites on
individual computers or networks, in order to limit a child's access to
pornographic materials or depiction of violence.
