The Internet

The Internet is a collection of networks spanning the globe, with a large number of research, educational and commercial networks connected together into one global network. It has gateways linking organizations throughout the world and yet it has no central, worldwide, technical control point. This loosely-organized, international collaboration of autonomous, interconnected networks, supports host-to-host communication through voluntary adherence to open protocols and procedures defined by Internet Standards.

At present, the organizations that connect through the Internet include corporations, universities and colleges, research laboratories -- government and private, libraries, specialized scientific centers, state agencies, K-12 (Kindergarten-12th Grade) organizations and individuals. Each one of these organizations has its own network which is in turn connected to the Internet. These smaller networks all use a common suite of networking protocols known as TCP/IP. This commonality of protocols, coupled with a commonality of network functionality and interoperability, creates what to a user seems to be a single, integrated, worldwide, virtual network.

The Internet serves as both a live test-bed for on-going networking research and a daily communications tool for millions of users. It is a major tool in academic and industrial research in computer technology, physics, and astronomy, and increasingly in biological, social, and other sciences.See "The Matrix", Matrix, for additional information. RFC-1296,RFCs (Request For Comment) are a series of Internet technical documents. About RFCs, for more details. RFC-1296, provides statistics on the growth of the Internet by examining the number of Internet hosts and domains over a 10-year period. As of January 1995, 4.8 million IP hosts were on the Internet.One easily computed measure of Internet connectivity is the count of host address records within the Domain Name System. Domain Name System (DNS). Estimates of number of users connected to Internet vary, depending upon the definition of connectivity used. It is estimated that some 20 million users around the world are linked through the Internet.

The Internet is growing at a phenomenal rate, with no deceleration in sight. Every month thousands of new users are added. New networks are added literally almost every half hour. During the period from 1981 to 1992 the number of hosts has nearly doubled every year. The current growth is running at some 118% per year. Figure (Internet Growth (1981-1991)) RFC-1296, illustrate the exponential rate at which the number of Internet hosts has been increasing through the past decade.

As expected, the traffic on the Internet has been growing as well. Figure illustrates the growth of traffic on the Internet, as measured by the number of packets of information sent through the network.

Not only has the population of Internet been growing at a phenomenal rate but the diversity of services available through Internet have been growing very rapidly and steadily as well. Internet-enabled interpersonal communication services in general, and electronic mail in particular are amongst the most popular features of Internet. Other "basic" functions provided are access to remote computational and informational facilities, and file transfer. Such informational facilities include distributed file systems, distributed bulletin board services (e.g., Usenet), a variety of distributed information systems and a very extensive network of file archives.

These services allow users to make available information to others, increase productivity through "cooperative work tools" or offer a way to share resources and coordinate work among users. This document primarily focuses on use of electronic mail in Internet.

The next sections provides an overview of Internet e-mail and related services.