INTERNET

I. INTRODUCTION  

Internet, open interconnection of computer networks that enables the computers and the programs they run to communicate directly. There are many small-scale, controlled-access "enterprise internets", but the term is usually applied to the global, publicly accessible network, called simply the Internet or Net. By early 2000, more than 100,000 networks and around 100 million users were connected via the Internet.

Internet connection is usually accomplished using international standards collectively called TCP/IP (Transmission Control Protocol/Internet Protocol), which are issued by an organization called the Internet Engineering Task Force, combined with a network registration process, and with the aid of public providers of Internet access services, known as Internet Service Providers.

Each computer network and connected computer—called an Internet host—is provided with a unique Internet Protocol (IP) address—198.105.232.1, for example. For obvious reasons, the IP address has become known as the "dot address" of a computer. Although very simple and effective for network operation, dot addresses are not very user-friendly. Hence the introduction of the Domain Name Service (DNS) that allows for the assignment of meaningful or memorable names to numbers. DNS allows Internet hosts to be organized around domain names: for example, "microsoft.com" is a domain assigned to the Microsoft Corporation, with the suffix "com" signifying a commercial organization. "ftp.microsoft.com" is an Internet host within that domain. Each part of the domain still has an IP or dot address, which is used by the network elements to deliver information. From a user point of view, though, the IP address is translated (or "resolved") by DNS into the now familiar format.

Internets are constructed using virtually any kind of electronic transmission medium, such as optical-fibre or copper-wire telephone lines, or radio or microwave channels. They can also connect almost any kind of computer or operating system; and they are operated in such a way as to be "self-aware" of their capabilities.

The great scale and universality of the public Internet results in its use to connect many other kinds of computer networks and services—including online information and shopping services—via systems called gateways. As a result of all these features, internets are an ideal means of building a very robust universal information infrastructure throughout the world. The rapid growth of online shops, information services, and electronic business applications is testament to the inherent flexibility of the Net.

II. SERVICES  

Internets support thousands of different kinds of operational and experimental services. A few of the most popular include the following:

E-mail (electronic mail) allows a message to be sent from one person to another, or to many others, via computer. Internet has its own e-mail standards that have also become the means of interconnecting most of the world's e-mail systems. Internet e-mail addresses usually have a form such as "editor@encarta.microsoft.com", where "editor" is the e-mail account name, and "encarta.microsoft.com" is the domain identity of the computer hosting the account. E-mail can also be used to create collaborative groups through the use of special e-mail accounts called "reflectors" or "exploders" that automatically redistribute mail sent to the address.

The World Wide Web allows the seamless creation and use of elegant point-and-click hypermedia presentations, linked across the Internet in a way that creates a vast open knowledge repository, through which users can easily browse.

Gopher is a system that allows the creation and use of directories of files held on computers on the Internet, and builds links across the Internet in a manner that allows users to browse through the files.

FTP (File Transfer Protocol) is a set of conventions allowing easy transfer of files between host computers. This remains the biggest use of the Internet, especially for software distribution, and many public distribution sites now exist.

Usenet allows automatic global distribution of news messages among thousands of user groups, called newsgroups.

Telnet is the system that allows a user to "log in" to a remote computer, and make use of it.

III. METHODS OF CONNECTING

There are four ways to connect to the public Internet.

Host access is usually carried out via dial-up telephone lines and modems, combined with internet software on a personal computer, and allows the computer that is accessed to function fully as an internet host.

Network access is similar to host access, but is done via a leased line, which makes a local or wide area network, and all the attached computers, into internet hosts.

Terminal access is usually carried out via dial-up telephone lines and modems combined with terminal emulation software on a personal computer; it allows interaction with another computer that is an internet host.

Gateway access is similar to terminal access, but is provided via on-line or similar proprietary services that give the user the ability to exchange e-mail with the Internet.

IV. HISTORY AND FUTURE

 The Internet technology was created by Vinton Cerf in early 1973 as part of a project headed by Robert Kahn and conducted by the Advanced Research Projects Agency, part of the United States Department of Defense. Thereafter, Cerf led many efforts to build, scale, and standardize the Internet. In 1984 the technology and the network were turned over to the private sector and to government scientific agencies for further development. The growth has continued exponentially. Service-provider companies that make "gateways" to the Internet available to home and business users enter the market in ever-increasing numbers. By early 2000, access was available in over 200 countries and encompassed around 100 million users. The Internet and its technology continue to have a profound effect in promoting the sharing of information, making possible rapid transactions among businesses, and supporting global collaboration among individuals and organizations. In 1999, 205 countries and territories in the world had at least one connection to the Internet. The development of the World Wide Web is fuelling the rapid introduction of new business tools and activities that may by then have led to annual business transactions on the Internet worth hundreds of billions of pounds. The potential of web-based commerce is immense. Techniques that allow safe transactions over the Net (for payment and funds transfers), the construction of faster, more secure networks and the development of efficient search techniques make the Internet an ideal trading medium.

Future concerns include the efficiency of search engines—even the most efficient of them cover less than a sixth of all publicly available pages—as well as privacy, security, and Internet piracy.