[ltr]
[size=32]Internet[/size][/ltr]
[ltr]The
Internet is the worldwide, publicly accessible network of interconnected
computer networks that transmit
data by
packet switching using the standard
Internet Protocol (IP). It is a "network of networks" that consists of millions of smaller domestic, academic, business, and government networks, which together carry various
information and services, such as
electronic mail,
online chat,
file transfer, and the interlinked
Web pages and other documents of the
World Wide Web.[/ltr]
[ltr]
Creation of the Internet[/ltr]
[ltr]The Internet is the worldwide, publicly accessible network of interconnected computer networks that transmit data by packet switching using the standard Internet Protocol (IP). It is a "network of networks" that consists of millions of smaller domestic, academic, business, and government networks, which together carry various information and services, such as electronic mail, online chat, file transfer, and the interlinked Web pages and other documents of the World Wide Web.[/ltr]
[ltr]The
USSR's launch of
Sputnik spurred the
United States to create the Advanced Research Projects Agency (ARPA, later known as the
Defense Advanced Research Projects Agency, or DARPA) in February 1958 to regain a technological lead. ARPA created the
Information Processing Technology Office (IPTO) to further the research of the
Semi Automatic Ground Environment (SAGE) program, which had networked country-wide radar systems together for the first time.
J. C. R. Licklider was selected to head the IPTO, and saw universal networking as a potential unifying human revolution.[/ltr]
[ltr]In
1950, Licklider moved from the Psycho-Acoustic Laboratory at
Harvard University to
MIT where he served on a committee that established
MIT Lincoln Laboratory. He worked on the SAGE project. In
1957 he became a Vice President at
BBN, where he bought the first production
PDP-1 computer and conducted the first public demonstration of
time-sharing.[/ltr]
[ltr]Licklider recruited
Lawrence Roberts to head a project to implement a network, and Roberts based the technology on the work of
Paul Baran who had written an exhaustive study for the U.S. Air Force that recommended
packet switching (as opposed to
Circuit switching) to make a network highly robust and survivable. After much work, the first node went live at
UCLA on
October 29, 1969 on what would be called the
ARPANET, one of the "eve" networks of today's Internet. Following on from this, the
British Post Office,
Western Union International and
Tymnet collaborated to create the first international packet switched network, referred to as the
International Packet Switched Service (IPSS), in 1978. This network grew from Europe and the US to cover Canada, Hong Kong and Australia by 1981.[/ltr]
[ltr]The first
TCP/IP wide area network was operational by 1 January 1983, when the United States'
National Science Foundation (NSF) constructed a university network backbone that would later become the
NSFNet. (This date is held by some to be technically that of the birth of the Internet.) It was then followed by the opening of the network to commercial interests in 1985. Important, separate networks that offered gateways into, then later merged with, the NSFNet include
Usenet,
Bitnet and the various commercial and educational
X.25 Compuserve and
JANET.
Telenet (later called Sprintnet), was a large privately-funded national computer network with free dialup access in cities throughout the U.S. that had been in operation since the 1970s. This network eventually merged with the others in the 1990s as the TCP/IP protocol became increasingly popular. The ability of TCP/IP to work over these pre-existing communication networks, especially the international X.25 IPSS network, allowed for a great ease of growth. Use of the term "Internet" to describe a single global TCP/IP network originated around this time.[/ltr]
[ltr]The network gained a public face in the 1990s. On August 6th, 1991
CERN, which straddles the border between
France and
Switzerland publicized the new World Wide Web project, two years after
Tim Berners-Lee had begun creating
HTML,
HTTP and the first few Web pages at
CERN.[/ltr]
[ltr]An early popular Web browser was
ViolaWWW based upon
HyperCard. It was eventually replaced in popularity by the
Mosaic Web Browser. In 1993 the
National Center for Supercomputing Applications at the
University of Illinois at Urbana-Champaign released version 1.0 of
Mosaic and by late 1994 there was growing public interest in the previously academic/technical Internet. By 1996 the word "Internet" was coming into common daily usage, frequently misused to refer to the
World Wide Web.[/ltr]
[ltr]Meanwhile, over the course of the decade, the Internet successfully accommodated the majority of previously existing public computer networks (although some networks such as
FidoNet have remained separate). 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.[/ltr]
[ltr]
Today's Internet[/ltr]
[ltr]
[/ltr]
[ltr]
[/ltr]
[ltr]Server Hosting the
My Opera Community on the Internet[/ltr]
[ltr]Aside from the complex 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 essentially defined by its interconnections and routing policies.[/ltr]
[ltr]As of
September 18,
2006, 1.09 billion people use the Internet according to
Internet World Stats.[/ltr]
[ltr]
Internet protocols[/ltr]
[ltr]In this context, there are three layers of protocols:[/ltr]
[ltr]
· At the lowest level is
IP (Internet Protocol), which defines the datagrams or
packets that carry blocks of data from one node to another. The vast majority of today's Internet uses version four of the IP protocol (i.e.
IPv4), and although
IPv6 is standardised, it exists only as "islands" of connectivity, and there are many ISPs who don't have any IPv6 connectivity at all.
[1] [/ltr]
[ltr]
· Next come
TCP (Transmission Control Protocol) and
UDP (User Datagram Protocol) - the protocols by which one host sends data to another. The former makes a virtual 'connection', which gives some level of guarantee of reliability. The latter is a best-effort, connectionless transport, in which data packets that are lost in transit will not be re-sent. [/ltr]
[ltr]
· On top comes the
application protocol. This defines the specific messages and data formats sent and understood by the applications running at each end of the communication. [/ltr]
[ltr]
The World Wide Web[/ltr]
[ltr]Through
keyword-driven
Internet research using
search engines, like
Google, millions worldwide have easy, instant access to a vast and diverse amount of online information. Compared to
encyclopedias and traditional
libraries, the World Wide Web has enabled a sudden and extreme decentralization of information and data.[/ltr]
[ltr]Many individuals and some companies and groups have adopted the use of "Web logs" or
blogs, which are largely used as easily-updatable online diaries. Some commercial organizations encourage staff to fill them with advice on 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.[/ltr]
[ltr]For more information on the distinction between the World Wide Web and the Internet itself — as in everyday use the two are sometimes confused — see
Dark internet where this is discussed in more detail.[/ltr]
[ltr]Internet Use :[/ltr]
[ltr]An International website featuring up to date free worldwide Internet Usage, the Population Statistics and Market Data, for over 233 countries and world regions. See the Big Picture
here.
A useful resource for international market research, containing Internet statistics, broadband penetration, world population data and global trade information. Web site is updated frequently.
Site navigation and usability has been made easy with links at the bottom of the pages, content menus on the left hand side column of most pages, and active links to country maps, statistics, local directories, and population information.
Market research reports are also available.
Remember to reload (refresh) web pages to get and display the latest updated statistics.[/ltr]
[ltr]
[/ltr]
[ltr]
File sharing[/ltr]
[ltr]A
computer file can be
e-mailed to customers, colleagues and friends as an
attachment. It can be uploaded to a
Web site 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 before or after access to the file is given. The price can be paid by the remote charging of funds from, for example a
credit card whose details are also passed - hopefully 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.[/ltr]
[ltr]These simple features of the Internet, over a world-wide basis, are changing the basis for the production, sale, and distribution of anything that can be reduced to a computer file for transmission. This includes all manner of office documents, publications, software products,
music, photography, video, animations, graphics and the other arts. This in turn is causing seismic shifts in each of the existing industry associations, such as the
RIAA and
MPAA in the United States, that previously controlled the production and distribution of these products in that country.[/ltr]
[ltr]
Streaming media[/ltr]
[ltr]Many existing radio and television broadcasters provide Internet 'feeds' of their live audio and video streams (for example, the
BBC). 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 licences. 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
TV or
radio receiver. The range of material is much wider, from
pornography to highly specialised technical Web-casts.
Podcasting is a variation on this theme, where—usually audio—material is first downloaded in full and then may be played back on a computer or shifted to a
digital audio 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 on a worldwide basis.[/ltr]
[ltr]
Webcams can be seen as an even lower-budget extension of this phenomenon. While some webcams can give full frame rate video, the picture is usually either small or updates slowly. Internet users can watch animals around an African waterhole, ships in the
Panama Canal, the traffic at a local roundabout or their own premises, live and in real time. Video
chat rooms,
video conferencing, and remote controllable webcams are also popular. Many uses can be found for personal webcams in and around the home, with and without two-way sound.[/ltr]
[ltr]
VoIP[/ltr]
[ltr]VoIP stands for Voice over IP, where
IP refers to the Internet Protocol that underlies all Internet communication. This phenomenon began as an optional two-way voice extension to some of the
Instant Messaging systems that took off around the year 2000. 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 actual voice traffic, VoIP can be free or cost much less than a normal telephone call, especially over long distances and especially for those with always-on
ADSL or
DSL Internet connections.[/ltr]
[ltr]Thus VoIP is maturing into a viable alternative to traditional telephones. Interoperability between different providers has improved and the ability to call or receive a call from a traditional telephone is available. Simple inexpensive VoIP modems are now available that eliminate the need for a PC.[/ltr]
[ltr]Voice quality can still vary from call to call but is often equal to and can even exceed that of traditional calls.[/ltr]
[ltr]Remaining problems for VoIP include
emergency telephone number dialing and reliability. Currently a few VoIP providers provide some 911 dialing but it is not universally available. Traditional phones are line powered and operate during a power failure, VoIP does not do so without a
backup power source for the electronics.[/ltr]
[ltr]Most VoIP providers offer unlimited national calling but the direction in VoIP is clearly toward global coverage with unlimited minutes for a low monthly fee.[/ltr]
[ltr]VoIP has also become increasingly popular within the gaming world, as a form of communication between players. Popular gaming VoIP clients include
Ventrilo and
Teamspeak, and there are others available also.[/ltr]
[ltr]
Censorship[/ltr]
[ltr]Some governments, such as those of
Iran and the
People's Republic of China 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.[/ltr]
[ltr]Many countries have enacted laws making the possession or distribution of certain material, such as
child pornography, illegal, but do not use filtering software.[/ltr]
[ltr]There are many free and commercially available software programs with which a user can choose to block offensive Web sites on individual computers or networks, such as to limit a child's access to pornography or violence. See
Content-control software.[/ltr]
[ltr]
Internet access[/ltr]
[ltr]
. [/ltr]
[ltr]
[/ltr]
[ltr]Internet public access point in
Brazil, 2004.[/ltr]
[ltr]Common methods of home access include
dial-up, landline
broadband (over coaxial cable, fibre optic or copper wires),
Wi-Fi,
satellite and
cell phones.[/ltr]
[ltr]
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.[/ltr]
[ltr]
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 a would-be user needs 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. The whole campus or park, or even the entire city can be enabled.
Grassroots efforts have led to
wireless community networks. Commercial WiFi services covering large city areas are in place in
London,
Vienna,
San Francisco,
Philadelphia,
Chicago,
Pittsburgh and other cities, including
Toronto by the end of 2006. The Internet can then be accessed from such places as a park bench.
[1][/ltr]
[ltr]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.[/ltr]
[ltr]High-end mobile phones such as smartphones generally 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. An internet access provider and protocol matrix differentiates the methods used to get online.[/ltr]
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