   #copyright

Internet

2007 Schools Wikipedia Selection. Related subjects: Media; Websites and the
Internet

   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.
   Visualization of the various routes through a portion of the Internet.
   Enlarge
   Visualization of the various routes through a portion of the Internet.

Terminology: Internet vs. Web

   The Internet and the World Wide Web are not synonymous: the Internet is
   a collection of interconnected computer networks, linked by copper
   wires, fibre-optic cables, wireless connections, etc.; the Web is a
   collection of interconnected documents and other resources, linked by
   hyperlinks and URLs. The World Wide Web is accessible via the Internet,
   as are many other services including e-mail, file sharing, and others
   described below.

   The best way to define and distinguish between these terms is to
   understand the Internet protocol suite. This collection of protocols is
   organized into layers such that each layer provides the foundation and
   the services required by the layer above. In this conception, the term
   Internet refers to computer networks that all communicate with IP
   (Internet protocol) and TCP (transfer control protocol). Once this
   networking structure is established, then other protocols can run “on
   top.” These other protocols are sometimes called services or
   applications. Hypertext transfer protocol, or HTTP, is an application
   layer protocol that links billions of files together into the World
   Wide Web.

Creation of the Internet

   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.

   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.

   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.

   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.

   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.

   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.

   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 Centre 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.

   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.

Today's Internet

   Server Hosting the My Opera Community on the Internet
   Enlarge
   Server Hosting the My Opera Community on the Internet

   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.

   As of September 18, 2006, 1.09 billion people use the Internet
   according to Internet World Stats.

Internet protocols

   In this context, there are three layers of protocols:
     * 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.
     * 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.
     * 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.

Internet structure

   There have been many analyses of the Internet and its structure. For
   example, it has been determined that the Internet IP routing structure
   and hypertext links of the World Wide Web are examples of scale-free
   networks.

   Similar to the way the commercial Internet providers connect via
   Internet exchange points, research networks tend to interconnect into
   large subnetworks such as:
     * GEANT
     * GLORIAD
     * Internet2
     * JANET (the UK's Joint Academic Network aka UKERNA)

   These in turn are built around relatively smaller networks. See also
   the list of academic computer network organizations

   In network schematic diagrams, the Internet is often represented by a
   cloud symbol, into and out of which network communications can pass.

ICANN

   The Internet Corporation for Assigned Names and Numbers (ICANN) is the
   authority that coordinates the assignment of unique identifiers on the
   Internet, including domain names, Internet protocol addresses, and
   protocol port and parameter numbers. A globally unified namespace
   (i.e., a system of names in which there is one and only one holder of
   each name) is essential for the Internet to function. ICANN is
   headquartered in Marina del Rey, California, but is overseen by an
   international board of directors drawn from across the Internet
   technical, business, academic, and non-commercial communities. The US
   government continues to have the primary role in approving changes to
   the root zone file that lies at the heart of the domain name system.
   Because the Internet is a distributed network comprising many
   voluntarily interconnected networks, the Internet, as such, has no
   governing body. ICANN's role in coordinating the assignment of unique
   identifiers distinguishes it as perhaps the only central coordinating
   body on the global Internet, but the scope of its authority extends
   only to the Internet's systems of domain names, Internet protocol
   addresses, and protocol port and parameter numbers.

   On Nov. 16, 2005, the World Summit on the Information Society, held in
   Tunis, established the Internet Governance Forum (IGF) to discuss
   Internet-related issues.
   Graphic representation of a very small part of the WWW, representing
   some of the hyperlinks
   Enlarge
   Graphic representation of a very small part of the WWW, representing
   some of the hyperlinks

Language

   The most prevalent language for communication on the Internet is
   English. This may be a result of the Internet's origins, as well as
   English's role as the lingua franca. It may also be related to the poor
   capability of early computers to handle characters other than those in
   the basic Latin alphabet.

   After English (30% of Web visitors) the most-requested languages on the
   World Wide Web are Chinese 14%, Japanese 8%, Spanish 8%, German 6%, and
   French 4% (from Internet World Stats, updated June 30, 2006).

   By continent, 37% of the world's Internet users are based in Asia, 28%
   in Europe, and 22% in North America ( updated June 30, 2006).

   The Internet's technologies have developed enough in recent years that
   good facilities are available for development and communication in most
   widely used languages. However, some glitches such as mojibake
   (incorrect display of foreign language characters, also known as
   krakozyabry) still remain.

Internet and the workplace

   The Internet is allowing greater flexibility in working hours and
   location, especially with the spread of unmetered high-speed
   connections and Web applications.

Common uses of the Internet

The World Wide Web

   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.

   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.

   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.

Remote access

   The Internet allows computer users to connect to other computers and
   information stores easily, wherever they may be across the world. They
   may do this with or without the use of security, 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 book-keepers, in other remote locations, based on
   information e-mailed 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 his desk, perhaps the other side of the
   world on a business trip or a holiday, can open a remote desktop
   session into his normal office PC using a secure Virtual Private
   Network (VPN) connection via the Internet. This gives him complete
   access to all his normal files and data, including e-mail and other
   applications, while he is away.

   This concept is also referred to by some network security people as the
   Virtual Private Nightmare, because it extends the secure perimeter of a
   corporate network into its employees' homes; this has been the source
   of some notable security breaches, but also provides security for the
   workers.

Collaboration

   The low-cost and nearly instantaneous sharing of ideas, knowledge, and
   skills has made collaborative work dramatically easier. Not only can a
   group cheaply communicate and test, but the wide reach of the Internet
   allows such groups to easily form in the first place, even among niche
   interests. An example of this is the Free/Libre/Open-Source Software
   (FLOSS) movement in software development, such as Linux, Mozilla, and
   OpenOffice.org. Cooperation has been greatly eased in other fields, as
   well.

   Internet 'chat', whether in the form of IRC 'chat rooms' or channels,
   or via instant messaging systems allow colleages to stay in touch in a
   very convenient way when working at their computers during the day.
   Messages can be send and viewed even more quickly and conveniently than
   via e-mail. Extension to these systems may allow files to be exchanged,
   'whiteboard' drawings to be shared as well as voice and video contact
   between team members.

   Version control systems allow collaborating teams to work on shared
   sets of documents without either accidentally overwriting each other's
   work or having members wait until they get 'sent' documents to be able
   to add their thoughts and changes.

File sharing

   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.

   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.

VoIP

   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.

   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.

   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 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.

   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.

   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.

Censorship

   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.

   Many countries have enacted laws making the possession or distribution
   of certain material, such as child pornography, illegal, but do not use
   filtering software.

   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.

Internet access

   Internet public access point in Brazil, 2004.
   Enlarge
   Internet public access point in Brazil, 2004.

   Common methods of home access include dial-up, landline broadband (over
   coaxial cable, fibre optic or copper wires), Wi-Fi, satellite and 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.

   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.

   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 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.

Leisure

   The Internet has been a major source of leisure since before the World
   Wide Web, with entertaining social experiments such as MUDs and MOOs
   being conducted on university servers, and humor-related Usenet groups
   receiving much of the main traffic. Today, many Internet forums 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 pornography and gambling industries have both taken full advantage
   of the World Wide Web, and often provide a significant source of
   advertising revenue for other Web sites. Although many governments have
   attempted to put restrictions on both industries' use of the Internet,
   this has generally failed to stop their widespread popularity. A song
   in the Broadway musical show Avenue Q is titled " The Internet is for
   Porn" and refers to the popularity of this aspect of the internet.

   One main area of leisure on the Internet is multiplayer gaming. This
   form of leisure creates communities, bringing people of all ages and
   origins to enjoy the fast-paced world of multiplayer games. These range
   from MMORPG to first-person shooters, from role-playing games to online
   gambling. This has revolutionized the way many people interact and
   spend their free time on the Internet.

   While online gaming has been around since the 1970s, modern modes of
   online gaming began with services such as GameSpy and MPlayer, which
   players of games would typically subscribe to. Non-subscribers were
   limited to certain types of gameplay or certain games.

   Many use the Internet to access and download music, movies and other
   works for their enjoyment and relaxation. As discussed above, there are
   paid and unpaid sources for all of these, using centralised servers and
   distributed peer-to-peer technologies. Discretion is needed as some of
   these sources take more care over the original artists' rights and over
   copyright laws than others.

   Many use the World Wide Web to access news, weather and sports reports,
   to plan and book holidays and to find out more about their random ideas
   and casual 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 Web sites like Friends Reunited and many others
   like them also put and keep people in contact for their enjoyment.

   Cyberslacking has become a serious drain on corporate resources; the
   average UK employee spends 57 minutes a day surfing the Web at work,
   according to a study by Peninsula Business Services .

Complex architecture

   Many computer scientists see the Internet as a "prime example of a
   large-scale, highly engineered, yet highly complex system". The
   Internet is extremely 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.

Marketing

   The Internet has also become a large market for companies; some of the
   biggest companies today have grown by taking advantage of the efficient
   nature of low-cost advertising and commerce through the Internet; also
   known as e-commerce. It is the fastest way to spread information to a
   vast amount of people simultaneously. The Internet has also
   subsequently revolutionized shopping—for example; a person can order a
   CD online and receive it in the mail within a couple of days, or
   download it directly in some cases. The Internet has also greatly
   facilitated personalized marketing which allows a company to market a
   product to a specific person or a specific group of people more so than
   any other advertising medium.

   Examples of personalized marketing include online communities such as
   Myspace, Friendster, and others which thousands of Internet users join
   to advertise themselves and make friends online. Many of these users
   are young teens and adolescents ranging from 13 to 25 years old. In
   turn, when they advertise themselves they advertise interests and
   hobbies, which online marketing companies can use as information as to
   what those users will purchase online, and advertise their own
   companies' products to those users.

   A very ineffective way of advertising on the internet is through
   spamming an email with advertisements. This is ineffective because,
   now, most email providers offer protection against email spam. Most
   spam messages are sent automatically to everybody in the email database
   of the company/person that is spamming. This way of advertising is
   almost like using adware.

   Adware is another ineffective way of advertising because most people
   simply close a popup window when it shows up, not bothering to read it.

The name Internet

   Internet is traditionally written with a capital first letter, as it is
   a proper noun. The Internet Society, the Internet Engineering Task
   Force, the Internet Corporation for Assigned Names and Numbers, the
   World Wide Web Consortium, and several other Internet-related
   organizations use this convention in their publications.

   Many newspapers, newswires, periodicals, and technical journals
   capitalize the term. Examples include the New York Times, the
   Associated Press, Time, The Times of India, Hindustan Times, and
   Communications of the ACM.

   Others assert that the first letter should be written in lower case
   (internet). A significant number of publications use this form,
   including The Economist, the Canadian Broadcasting Corporation, the
   Financial Times, The Guardian, The Times, and The Sydney Morning
   Herald. As of 2005, many publications using internet appear to be
   located outside of North America—although one U.S. news source, Wired
   News, has adopted the lower case spelling.

   Historically, Internet and internet have had different meanings, with
   internet being a contraction of internetwork or internetworking and
   Internet referring to the worldwide network. Under this distinction,
   the Internet is a particular internet, but the reverse does not apply.
   The distinction was evident in many RFCs, books, and articles from the
   1980s and early 1990s (some of which, such as RFC 1918, refer to
   "internets" in the plural), but has recently fallen into disuse.

Significant Internet events

Malfunctions and attacks

     * SQL Slammer worm — January 24, 2003
     * 2002 DNS Backbone DDoS — October 22, 2002
     * UUNet/Worldcom backbone difficulties — October 3, 2002
     * Predicted Y2K Bug - January 1, 2000
     * Morris worm — November 2, 1988

   Retrieved from " http://en.wikipedia.org/wiki/Internet"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
   Documentation License. See also our Disclaimer.
