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Internet, the, international computer network linking together thousands of individual networks at military and government agencies, educational institutions, nonprofit organizations, industrial and financial corporations of all sizes, and commercial enterprises (called gateways or service providers) that enable individuals to access the network. The most popular features of the Internet include electronic mail (e-mail), blogs (web logs or journals), discussion groups (such newsgroups, bulletin boards, or forums where users can post messages and look for responses), on-line conversations (such as chats or instant messaging), wikis (websites that anyone on the Internet can edit), adventure and role-playing games, information retrieval, electronic commerce (e-commerce), messaging, Internet-based telephone service (voice over IP [VoIP]), and web mashups (in which third parties combine their web-based data and services with those of other companies).
The public information stored in the multitude of computer networks connected to the Internet forms a huge electronic library, but the enormous quantity of data and number of linked computer networks also make it difficult to find where the desired information resides and then to retrieve it. A number of progressively easier-to-use interfaces and tools have been developed to facilitate searching. Among these are search engines, such as Archie, Gopher, and WAIS (Wide Area Information Server), and a number of commercial, Web-based indexes, such as Google, Bing, and Yahoo, which are programs that use a proprietary algorithm or other means to search a large collection of documents for keywords and return a list of documents containing one or more of the keywords. Telnet is a program that allows users of one computer to connect with another, distant computer in a different network. The File Transfer Protocol (FTP) is used to transfer information between computers in different networks. The greatest impetus to the popularization of the Internet came with the introduction of the World Wide Web (WWW), a hypertext system that makes browsing the Internet both fast and intuitive. Most e-commerce occurs over the Web, and most of the information on the Internet now is formatted for the Web, which has led Web-based indexes to eclipse the other Internet-wide search engines.
Each computer that is directly connected to the Internet is uniquely identified by a binary number called its IP address. Most computers presently use an Internet Protocol version 4 (IPv4) address, which is 32 bits in size. This address is usually seen as a four-part decimal number, such as 220.127.116.11, with each part equating to 8 bits (1 byte) of the 32-bit address in the decimal range 0–255; the parts are separated by dots (periods). Although the number of addresses available under IPv4 is roughly 4.3 billion, the number of unassigned addresses will soon be depleted.
The Internet is transitioning to IP version 6 (IPv6) addressing, which uses 128 bits to represent an address. An IPv6 address is usually represented as an eight-part hexadecimal number (see numeration); each part is equivalent to 16 bits (2 bytes) of the 128-bit address in the hexadecimal range 0000–ffff, and colons are used to separate the parts. An IPv6 address such as 1234:0000:0000:0000:1234:5678:9abc:deff may also be represent by a shorthand version, 1234::1234:5678:9abc:deff, which does not show bytes with a zero value. IPv6 allows for some 3.4 × 1038 addresses.
Because an address of the form 18.104.22.168 is usually difficult to remember, a system of Internet addresses, or domain names, was developed in the 1980s. An Internet address is translated into an IP address by a domain-name server, a program running on an Internet-connected computer. Reading from left to right, the parts of a domain name go from specific to general. For example, www.college.columbia.edu is a World Wide Web site for Columbia College, which is part of Columbia Univ., which is an educational institution. The rightmost part, or top-level domain (or suffix or zone), can be a two-letter abbreviation of the country in which the computer is in operation; more than 250 abbreviations, such as “ca” for Canada and “uk” for United Kingdom, have been assigned. Although such an abbreviation exists for the United States (us), it is more common for a site in the United States to use a generic top-level domain such as edu (educational institution), gov (government), or mil (military) or one of the four domains originally designated for open registration worldwide, com (commercial), int (international), net (network), or org (organization). In 2000 seven additional top-level domains (aero, biz, coop, info, museum, name, and pro) were approved for worldwide use, and other domains, including the regional domains asia and eu, have since been added. In 2008 new rules were adopted that would allow a top-level domain to be any group of letters, but the final approval for proceeding with the creation of such domain names (beginning in 2012) waited until 2011. In 2009 further rules changes permitted the use of other writing systems in addition to the Latin alphabet in domain names (beginning in 2010).
The Internet evolved from a secret feasibility study conceived by the U.S. Dept. of Defense in 1969 to test methods of enabling computer networks to survive military attacks, by means of the dynamic rerouting of messages. As the ARPAnet (Advanced Research Projects Agency network), it began by connecting three networks in California with one in Utah—these communicated with one another by a set of rules called the Internet Protocol (IP). By 1972, when the ARPAnet was revealed to the public, it had grown to include about 50 universities and research organizations with defense contracts, and a year later the first international connections were established with networks in England and Norway.
A decade later, the Internet Protocol was enhanced with a set of communication protocols, the Transmission Control Program/Internet Protocol (TCP/IP), that supported both local and wide-area networks. Shortly thereafter, the National Science Foundation (NSF) created the NSFnet to link five supercomputer centers, and this, coupled with TCP/IP, soon supplanted the ARPAnet as the backbone of the Internet. In 1995 the NSF decommissioned the NSFnet, and responsibility for the Internet was assumed by the private sector. Progress toward the privatization of the Internet continued when Internet Corporation for Assigned Names and Numbers (ICANN), a nonprofit U.S. corporation, assumed oversight responsibility for the domain name system in 1998 under an agreement with the U.S. Dept. of Commerce.
Fueled by the increasing popularity of personal computers, e-mail, and the World Wide Web (which was introduced in 1991 and saw explosive growth beginning in 1993), the Internet became a significant factor in the stock market and commerce during the second half of the decade. By 2000 it was estimated that the number of adults using the Internet exceeded 100 million in the United States alone. In 2010 it was estimated that there were 2 billion Internet users worldwide; by the end of 2018 the estimate was 3.9 billion users, or more than half the world's population.
The increasing globalization of the Internet led a number of nations to call for oversight and governance of the Internet to pass from the U.S. government and ICANN to an international body, but a 2005 international technology summit agreed to preserve the status quo while establishing an international forum for the discussion of Internet policy issues. Revelations of U.S. Internet spying beginning in 2013 gave new impetus to end U.S. oversight of ICANN. In 2016 the U.S. Commerce Dept. handed over its largely perfunctory control of ICANN to stakeholder organizations and committees consisting of business, government, and other representatives. A number of nations have undertaken to limit their citizens' access to the Internet worldwide; China, whose so-called Great Firewall largely prevents Chinese users from accessing foreign sites, is probably the best known example. As reliance on the Internet for day-to-day communication and information access has increased, an even greater number of nations have shut down Internet access during political crises in order to make it hard for people to organize and protest.
See S. Coleman and J. G. Blumler, The Internet and Democratic Citizenship (2009); J. Ryan, A History of the Internet and the Digital Future (2010); J. Brockman, ed., Is the Internet Changing the Way You Think? (2011); S. Levmore and M. C. Nussbaum, ed., The Offensive Internet (2011); E. Pariser, The Filter Bubble: What the Internet Is Hiding from You (2011); J. Lanier, You Are Not a Gadget: A Manifesto (2011).
Internetthe global, distributed packet-switching network that interconnects computers. The Internet was initially developed by the US Defense Department in the 1970s as a safeguard against the failure of military communications systems during a nuclear attack. By the mid-1980s Internet technology was being appropriated by educational and research institutions as well as businesses and government organizations where it was widely viewed as an opportunity to document and access information. The Internet is now present in millions of organizations and private households around the globe and is essentially available to anyone with access to a personal computer and a telephone line. Its wide variety of uses range from what are regarded as legitimate applications such as advertising, shopping, library catalogues, newspaper archives, and financial pages, to its use for recreational or illicit 'S urfing’: ‘chat-rooms’, gossip, and eroticism. Because of its use by individuals and groups wanting to broadcast and access illicit or illegal material, the Internet is often regarded as providing a democratic forum for underground subcultures and organizations to communicate their desires, beliefs, and political agendas. These democratizing implications also extend to the economy with consumers being able to access the best (cheapest) prices and products available. However, there is the issue that these possibilities remain limited to those with access to the technology and knowledge. The immense amount of information available on the Internet and the know-how required to make effective use of the technology restrict the applications for the average 'S urfer’ who may spend hours moving between trivial sites. Alongside possibilities for global networking runs the danger that information-rich countries will monopolize both the technology and know-how required to distribute information and exclude dispossessed nations from the advantages available to those with access to the World Wide Web. See also CYBERCULTURE, INFORMATION SOCIETY, NETWORK SOCIETY.
A worldwide system of interconnected computer networks. The origins of the Internet can be traced to the creation of ARPANET (Advanced Research Projects Agency Network) as a network of computers under the auspices of the U.S. Department of Defense in 1969. Today, the Internet connects millions of computers around the world in a nonhierarchical manner unprecedented in the history of communications. The Internet is a product of the convergence of media, computers, and telecommunications. It is not merely a technological development but the product of social and political processes, involving both the academic world and the government (the Department of Defense). From its origins in a nonindustrial, noncorporate environment and in a purely scientific culture, it has quickly diffused into the world of commerce.
The Internet is a combination of several media technologies and an electronic version of newspapers, magazines, books, catalogs, bulletin boards, and much more. This versatility gives the Internet its power.
The Internet's technological success depends on its principal communication tools, the Transmission Control Protocol (TCP) and the Internet Protocol (IP). They are referred to frequently as TCP/IP. A protocol is an agreed-upon set of conventions that defines the rules of communication. TCP breaks down and reassembles packets, whereas IP is responsible for ensuring that the packets are sent to the right destination.
Data travels across the Internet through several levels of networks until it reaches its destination. E-mail messages arrive at the mail server (similar to the local post office) from a remote personal computer connected by a modem, or a node on a local-area network. From the server, the messages pass through a router, a special-purpose computer ensuring that each message is sent to its correct destination. A message may pass through several networks to reach its destination. Each network has its own router that determines how best to move the message closer to its destination, taking into account the traffic on the network. A message passes from one network to the next, until it arrives at the destination network, from where it can be sent to the recipient, who has a mailbox on that network. See Electronic mail, Local-area networks, Wide-area networks
TCP/IP is a set of protocols developed to allow cooperating computers to share resources across the networks. The TCP/IP establishes the standards and rules by which messages are sent through the networks. The most important traditional TCP/IP services are file transfer, remote login, and mail transfer.
The file transfer protocol (FTP) allows a user on any computer to get files from another computer, or to send files to another computer. Security is handled by requiring the user to specify a user name and password for the other computer.
The network terminal protocol (TELNET) allows a user to log in on any other computer on the network. The user starts a remote session by specifying a computer to connect to. From that time until the end of the session, anything the user types is sent to the other computer.
Mail transfer allows a user to send messages to users on other computers. Originally, people tended to use only one or two specific computers. They would maintain “mail files” on those machines. The computer mail system is simply a way for a user to add a message to another user's mail file.
Other services have also become important: resource sharing, diskless workstations, computer conferencing, transaction processing, security, multimedia access, and directory services.
TCP is responsible for breaking up the message into datagrams, reassembling the datagrams at the other end, resending anything that gets lost, and putting things back in the right order. IP is responsible for routing individual datagrams. The datagrams are individually identified by a unique sequence number to facilitate reassembly in the correct order. The whole process of transmission is done through the use of routers. Routing is the process by which two communication stations find and use the optimum path across any network of any complexity. Routers must support fragmentation, the ability to subdivide received information into smaller units where this is required to match the underlying network technology. Routers operate by recognizing that a particular network number relates to a specific area within the interconnected networks. They keep track of the numbers throughout the entire process.
Domain Name System
The addressing system on the Internet generates IP addresses, which are usually indicated by numbers such as 22.214.171.1240. Since such numbers are difficult to remember, a user-friendly system has been created known as the Domain Name System (DNS). This system provides the mnemonic equivalent of a numeric IP address and further ensures that every site on the Internet has a unique address. For example, an Internet address might appear as . If this address is accessed through a Web browser, it is referred to as a URL (Uniform Resource Locator), and the full URL will appear as .
The Domain Name System divides the Internet into a series of component networks called domains that enable e-mail (and other files) to be sent across the entire Internet. Each site attached to the Internet belongs to one of the domains. Universities, for example, belong to the “edu” domain. Other domains are gov (government), com (commercial organizations), mil (military), net (network service providers), and org (nonprofit organizations).
World Wide Web
The World Wide Web (WWW) is based on technology called hypertext. The Web may be thought of as a very large subset of the Internet, consisting of hypertext and hypermedia documents. A hypertext document is a document that has a reference (or link) to another hypertext document, which may be on the same computer or in a different computer that may be located anywhere in the world. Hypermedia is a similar concept except that it provides links to graphic, sound, and video files in addition to text files.
In order for the Web to work, every client must be able to display every document from any server. This is accomplished by imposing a set of standards known as a protocol to govern the way that data are transmitted across the Web. Thus data travel from client to server and back through a protocol known as the HyperText Transfer Protocol (http). In order to access the documents that are transmitted through this protocol, a special program known as a browser is required, which browses the Web.
Commerce on the Internet
Commerce on the Internet is known by a few other names, such as e-business, Etailing (electronic retailing), and e-commerce. The strengths of e-business depend on the strengths of the Internet. Internet commerce is divided into two major segments, business-to-business (B2B) and business-to-consumer (B2C). In each are some companies that have started their businesses on the Internet, and others that have existed previously and are now transitioning into the Internet world. Some products and services, such as books, compact disks (CDs), computer software, and airline tickets, seem to be particularly suited for online business.
Until the advent of the World-Wide Web in 1990, the Internet was almost entirely unknown outside universities and corporate research departments and was accessed mostly via command line interfaces such as telnet and FTP. Since then it has grown to become an almost-ubiquitous aspect of modern information systems, becoming highly commercial and a widely accepted medium for all sort of customer relations such as advertising, brand building, and online sales and services. Its original spirit of cooperation and freedom have, to a great extent, survived this explosive transformation with the result that the vast majority of information available on the Internet is free of charge.
While the web (primarily in the form of HTML and HTTP) is the best known aspect of the Internet, there are many other protocols in use, supporting applications such as electronic mail, Usenet, chat, remote login, and file transfer.
There were 20,242 unique commercial domains registered with InterNIC in September 1994, 10% more than in August 1994. In 1996 there were over 100 Internet access providers in the US and a few in the UK (e.g. the BBC Networking Club, Demon, PIPEX).
There are several bodies associated with the running of the Internet, including the Internet Architecture Board, the Internet Assigned Numbers Authority, the Internet Engineering and Planning Group, Internet Engineering Steering Group, and the Internet Society.
See also NYsernet, EUNet.
The Internet Index - statistics about the Internet.
InternetThe term internet (lower case "i") always meant a large network made up of smaller networks. Today, the term mostly refers to the global Internet, spelled with both upper and lower case "I."
The global Internet comprises over a billion Web, email and related servers in more than 100 countries. Originally developed for the U.S. military, it became widely used for academic and commercial research with access to unpublished data and journals on many subjects. As of 2020, nearly five billion people use the Internet, the majority of which are in Asia. Needless to say, the Internet has become indispensable to the world economy.
Not only is the "Net" the largest source of information on every subject known to humankind, it is also the greatest source of misinformation (unintentional) and disinformation (intentional falsehoods). The highest traffic on the Internet is video streaming followed by everything else, including websites and Web apps, email, voice, chat, backup, app updating and machine-to-machine communications.
Email Lit the Fuse
In the mid-1990s, the Internet surged in growth, increasing a hundredfold in 1995 and 1996 alone. The first reason was email. Up to that point, the major online services, such as AOL and CompuServe, provided email only to their respective customers. As they began to reach out to Internet users by interfacing with the Internet's mail system, the Internet took on the role of a global email gateway. For the first time, an AOL member could send messages to a CompuServe member, and vice versa. The Internet glued the world together for email, and every service eventually switched to the Internet's own mail protocol (see SMTP).
The Bomb Exploded with the Web
Secondly, with the advent of graphics-based Web browsers such as Mosaic and Netscape Navigator with Microsoft's Internet Explorer close behind, the World Wide Web took off. The Web became available to users with PCs and Macs rather than only to scientists and programmers at Unix workstations. Delphi was the first proprietary online service to offer Web access, and the others followed. Coming out of the woodwork, Internet service providers (ISPs) offered access to everyone, and the Web grew exponentially, soon becoming the majority of Internet traffic. Later, video streaming superseded Web pages. See ISP, HTTP and HTML.
Although daily news and information is available on countless websites, long before the Web, information on myriad subjects was exchanged via the User Network newsgroups (see Usenet). Still around, newsgroup articles can be selected and read directly from a Web browser.
Chat rooms provide another popular Internet service. Internet Relay Chat (see IRC) offers multiuser text conferencing on diverse topics. Dozens of IRC servers provide hundreds of channels that anyone can log in to and participate via the keyboard.
The Original Internet
The Internet started in 1969 as the ARPAnet. Funded by the U.S. government, ARPAnet became a series of high-speed links between major supercomputer sites and educational and research institutions worldwide, although mostly in the U.S. A major part of its backbone was the National Science Foundation's NSFNet. Along the way, it became known as the "Internet" or simply "the Net." By the 1990s, so many networks had connected and so much traffic was no longer educational or pure research that the Internet was on its way to becoming a commercial venture.
It Went Commercial in 1995
In 1995, the Internet was turned over to large commercial Internet providers (ISPs), such as MCI, Sprint and UUNET, which took responsibility for the backbones and have increasingly enhanced their capacities ever since. Regional ISPs link into these backbones to provide lines for their subscribers, and smaller ISPs hook either directly into the national backbones or into the regional ISPs.
The TCP/IP Protocol
Internet computers use the TCP/IP communications protocol. An Internet server, no matter its size, is a "host" and always online via TCP/IP, providing email, Web and other services. In the past, the Internet was connected to non-TCP/IP networks through gateways that converted TCP/IP into other protocols. See TCP/IP.
Access Was Originally Command Driven
Before the Web and graphics-based Web browsers, academicians and scientists accessed the Internet using command-driven Unix utilities. Some of these utilities are still used for all platforms. For example, FTP (file transfer program) is used to upload and download files, and Telnet lets a user log in to a host and run a program. See FTP, Telnet, Archie, Gopher and Veronica.
The Next Internet
Ironically, some of the original academic and scientific users of the Internet have developed their own Internet once again. Internet2 is a high-speed academic research network that was started in much the same fashion as the original Internet (see Internet2). See Web vs. Internet, IoT, World Wide Web, how to search the Web, intranet, NAP, hot topics and trends, IAB, information superhighway and online service.
|These four nodes were drawn in 1969 showing the University of California at Berkeley and Los Angeles, SRI International and the University of Utah. This modest network diagram was the beginning of the ARPAnet and eventually the Internet. (Image courtesy of The Computer History Museum, www.computerhistory.org)|
|How the Internet Is Connected|
|Small Internet service providers (ISPs) hook into regional ISPs, which link into major backbones that traverse the U.S. This diagram is conceptual because ISPs often span county and state lines.|