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For the more general networking concept, see computer network and internetworking.

The Internet, or simply the Net, is the worldwide, publicly accessible system of interconnected computer networks that transmit data by packet switching using the standard Internet Protocol (IP). It consists of millions of smaller business, academic, domestic, and government networks, which together carry various information and services, such as electronic mail, online chat, and the interlinked Web pages and other documents of the World Wide Web.

Contrary to some common usage, the Internet and the World Wide Web are not synonymous: the Internet is a collection of interconnected computer networks, linked by copper wires, fiber-optic cables, wireless connections etc.; the Web is a collection of interconnected documents, linked by hyperlinks and URLs, and is accessible using the Internet. In other words, the Internet is the hardware (the name for the network), and the World Wide Web is the software (its content).

Contents 1 Creation of the Internet 2 Today's Internet 2.1 Internet protocols 2.2 Internet structure 2.3 ICANN 2.4 The World Wide Web 2.5 Remote access 2.6 Collaboration 2.7 File-sharing 2.8 Streaming media 2.9 VoIP 2.10 Language 2.11 Internet and the workplace 3 Censorship 4 Internet access 5 Capitalization conventions 6 Leisure 7 A complex system 8 Marketing 9 Significant Internet events 9.1 Malfunctions and attacks 10 See also 11 References 11.1 Citations and notes 11.2 General 12 External links 12.1 General 12.2 Articles 12.3 History

Creation of the Internet

Main article: History of the Internet

The Internet was invented by The Tooth. The USSR's launch of Sputnik spurred the U.S. to create the Defense Advanced Research Projects Agency (DARPA) in February 1958 to regain a technological lead. DARPA created the Information Processing Technology Office (IPTO) to further the research of the Semi Automatic Ground Environment 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. 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, the "eve" network of today's Internet. In December of 1970, Charles A. Petrik contacted the U.S. Navy and suggested that a special communications network, which the Department of Defense had built for use in the possiblitity of a nuclear attack, could also be used during peace time. Petrik convinced the military to connect the computers of the U.S. National Laboratories for scientific research purposes, and to allow these labs to get data to other labs faster, and safer.

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 1995. Important separate networks that offered gateways into, then later merged into 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 1970's. This network eventually merged with the others in the 90's as the TCP/IP protocol became increasingly popular. The ability of TCP/IP to work over these pre-existing communication networks allowed for a great ease of growth. Use of Internet as a phrase to describe a single global TCP/IP network originated around this time.

The network gained a public face in the 1990s. In August 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. In 1993 the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign released the Mosaic web browser version 1.0, and by late 1994 there was growing public interest in the previously academic/technical Internet. By 1996 the word "Internet" was common public currency, but it referred almost entirely 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

Aside from the complex physical connections that make up its infrastructure, the Internet is held together by bi- or multi-lateral commercial contracts (for example 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 January 2006, over 1 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, 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]
• Next comes TCP and UDP - 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, connection-less 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.

Unlike older communications systems, the Internet protocol suite was deliberately designed to be independent of the underlying physical medium. Any communications network, wired or wireless, that can carry two-way digital data can carry Internet traffic. Thus, Internet packets flow through wired networks like copper wire, coaxial cable, and fibre optic, and through wireless networks like Wi-Fi. Together, all these networks, sharing the same protocols, form the Internet.

The Internet protocols originate from discussions within the Internet Engineering Task Force (IETF) and its working groups, which are open to public participation and review. These committees produce documents that are known as Request for Comments documents (RFCs). Some RFCs are raised to the status of Internet Standard by the IETF process.

Some of the most-used application protocols in the Internet protocol suite are DNS, POP3, IMAP, SMTP, HTTP, HTTPS and FTP. There are many other important ones; see the lists provided in these articles.

All services on the Internet make use of defined application protocols. Of these, e-mail and the World Wide Web are among the most well known, and other services are built upon these, such as mailing lists and blogs. There are many others that are necessary 'behind the scenes' and yet others that serve specialised requirements.

Some application protocols were not created out of the IETF process, but initially as part of proprietary commercial or private experimental systems. They became much more widely used and have now become de facto or actual standards in their own right. Examples of these include IRC chat rooms, and various instant messaging and peer-to-peer file sharing protocols.

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 how 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

Main article: 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.

The World Wide Web

Main article: 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 'weblogs' 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.

Collaboration

This low-cost and nearly instantaneous sharing of ideas, knowledge and skills has revolutionized some, and given rise to whole new, areas of human activity. One example of this is the collaborative development and distribution of Free/Libre/Open-Source Software (FLOSS) such as Linux, Mozilla and OpenOffice.org. See Collaborative software.

File-sharing

Main article: File sharing

A computer file can be e-mailed 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 networking.

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 many types of product, wherever they 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 USA, that previously controlled the production and distribution of these products in that country.

Streaming media

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.

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.

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.

Language

Main article: English on the Internet

The most prevalent language for communication on the Internet is English. This may be due to 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.

Further information: Unicode

After English (32% of web visitors) the most-requested languages on the world wide web are Chinese 13%, Japanese 8%, Spanish 7%, German 6% and French 4% (from Internet World Stats, updated November 30, 2005).

By continent, 34% of the world's Internet users are based in Asia, 29% in Europe, and 23% in North America ([2] updated November 21, 2005).

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 krakozyabry (also known as mojibake) still remain.

Internet and the workplace

With the emergence of the internet and recent high speed connections becoming available to the public, the internet has altered the way many people work in significant ways. Contrary to the traditional 9-5 workday where employees commute to and from work, the internet has allowed greater flexibility both in terms of working hours and work location. Today, many employees work from home by "telecommuting".

The internet and the advent of blogs has given employees a forum from which to voice their opinions about their jobs, employers and co-workers, creating a massive amount of information and data on work that is currently being collected by the Worklifewizard.org project run by Harvard Law School's Labor & Worklife Program.

Censorship

Main article: Censorship in cyberspace

Some governments, such as in Iran and China restrict what people in their countries can access on the Internet, especially political and religious content. Many of these country made into law of distributing materials that's considered illegal.

Censorship is sometimes done through government controlled censoring filters (in the cases of Iran and China supplied by large US corporations). However, many internet users are able to bypass these filters, meaning that most Internet content is accessible regardless of where one is in the world, so long as one has the technical skill and means of connecting to it.

Censorship can also be effected by means of law or culture, making the propagation of targeted materials extremely risky. In the UK, possession of censored material, such as child pornography, is a criminal offence.

There are a large number of programs available that will block what are deemed to be offensive Web sites (such as pornographic or violent) on individual computers or networks; they are variously known as "Internet filters" or "Censorware".

Internet access

Main article: Internet access

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, San Francisco, Philadelphia, Chicago, and other cities, including Toronto by the end of 2006. The Internet can then be accessed from such places as a park bench.^[1]

Apart from Wi-Fi, there have been experiments with proprietary mobile wireless networks like Ricochet, various high-speed data services over cellular or mobile phone networks, and fixed wireless services.

High end mobile phones such as Symbian 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.

Capitalization conventions

Main article: Internet capitalization conventions

Internet is traditionally written with a capital first letter. 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 small (internet). A significant number of publications use this form, including The Economist, 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.

However, one should consider that Internet and internet have historically different meanings. IBM's "TCP/IP Tutorial and Technical Overview" ISBN 0738421650 stated in 1989 that:

The words internetwork and internet is (sic) simply a contraction of the phrase interconnected network. However, when written with a capital "I", the Internet refers to the worldwide set of interconnected networks. Hence, the Internet is an internet, but the reverse does not apply. The Internet is sometimes called the connected Internet.

Thus, historical usage differentiated between the common noun, with a lower case first letter, and the proper noun, with an upper case first letter.

Leisure

The Internet has been a major source of leisure since before the World Wide Web, with entertaining social experiments such as 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 neta; short cartoons in the form of Flash movies are also popular.

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.

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. With the release of Diablo by Blizzard Entertainment, gamers were treated to a built in online game service that was free of charge over Battle.net. With Blizzard's next game, StarCraft, the gaming world saw an explosion in the numbers of players using the Internet to play multi-player games. StarCraft may have been the first non-MMO game in which most players utilized the online gameplay as opposed to the single-player gameplay. Recently with the release of World Of Warcraft (WOW) many users spend hours in a day trying to level up their characters.

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[3].

A complex system

Many computer scientists see the Internet as a "prime example of a large-scale, highly engineered, yet highly complex system" (Willinger, et al). 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 moreso 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.

Significant Internet events

Malfunctions and attacks

• 2003 North America blackout - August 14, 2003
• SQL Slammer worm - January 24, 2003
• 2002 DNS Backbone DDoS - October 22, 2002
• UUNet/Worldcom backbone difficulties - October 3, 2002
• Morris worm

See also

• List of Internet topics
• Art on the Internet
• Bogon filtering
• Catenet
• Central ad server
• Communications Opportunity, Promotion and Enhancement Act of 2006
• Cybersex
• Cyberzine
• Dark internet
• Download
• Democracy on the Internet
• Dynamics of the Internet
• E-mail
• Extranet
• File Sharing
• Flaming
• Friendship on the Internet
• Hacktivism or Hacker culture
• History of the Internet
• Hypertext Transfer Protocol (HTTP)
• Humor on the Internet
• ICANN
• Instant Messaging
• International Freedom of Expression eXchange - monitors Internet censorship around the world
• Internet 2
• Internet Archive
• Internet forum
• Internet pornography
• Internet Relay Chat
• Internet Service Provider
• Internet traffic engineering
• Internets (colloquialism)
• Interweb
• Intranet
• Modem
• NANOG
• Net Neutrality
• Netiquette
• Network Mapping
• Object hyperlinking
• Online banking
• Open Directory Project
• Privacy on the Internet
• Search engine
• Security breaches
• Server
• TOTSE
• Slang on the Internet
• Trolls and trolling
• Upload
• Videotex - an early communications technology
• Web browser
• Web hosting
• Web portal
• WebQuest
• World Wide Web
• Web Design

References

Citations and notes

General

• Living Internet -- Internet history and related information, including information from many creators of the Internet.
• First Monday peer-reviewed journal on the internet
• Walter Willinger, Ramesh Govindan, Sugih Jamin, Vern Paxson, and Scott Shenker. (2002). Scaling phenomena in the Internet. In Proceedings of the National Academy of Sciences, 99, suppl. 1, 2573 – 2580.

External links

General

• Example of an internet site
• Read Congressional Research Service (CRS) Reports regarding the Internet
• Internet access stats
• Glossary of Computer and Internet Terms
• Internet Health Report from Keynote
• Internet World Stats

Articles

• "EU and U.S. clash over control of the Net" - International Herald Tribune article by Tom Wright
• "10 Years that changed the world" - WiReD looks back at the evolution of the Internet over last 10 years
• Internet Explained Seven part article explaining the origins to the present and a summary for future of the Internet.
• John Walker: The Digital Imprimatur
• How Stuff Works explanation of the Infrastructure of the Internet
• "It's Just the 'internet' Now" - Wired.com article by Tony Long

History

• The Internet Society History Page
• How the Internet Came to Be
• Hobbes' Internet Timeline v8.1
• Futures and Non-futures for Scholarly Internet.
• History of the Internet links
• RFC 801, planning the TCP/IP switchover
• Video of a report on the Internet - before the Web
• Vinton Cerf's short history of the Internet
• Internet Archive - A searchable database of old cached versions of websites dating back to 1996
• A comprehensive history with people, concepts and many interesting quotations
• A list of lectures, some of which relate to the Internet, from the Massachusetts Institute of Technology is available here. Of particular interest is lecture #3 The Next Big Thing: Video Internet which is delivered in Real Player format. The lecture gives a brief history of networking; discusses convergence between the Internet/telephone/television networks; the expansion of broadband access; makes predictions about the future of delivery of video over the Internet.