WHAT IS THE INTERNET? The Internet is a worldwide network of networks which interconnects computers ranging from desktop Macs to the largest supercomputers. No one knows how large the Internet is. Some estimates range as high as two million computers used by close to 20 million people. No one is in charge of the Internet and because it is so large and complex, no one understands everything about it. One thing that is clear, and that is the Internet is rich in information resources of all kinds and expanding at a very rapid rate. You can use the Internet to view artwork, to listen to music, to access library catalogs and databases, to obtain software or electronic books, to get the latest satellite weather maps, to communicate with friends on the other side of the world, and to do additional things that weren't even dreamed about when this sentence was written. For those of you who care about technical considerations, all of the computers on the Internet communicate with one another using the Transmission Control Protocol/Internet Protocol suite, usually called TCP/IP. The Internet is often called a TCP/IP network.
WHAT IS WORLD WIDE WEB (MOSAIC)? World Wide Web (abbreviated as WWW) is an innovative hypertext front end program based on client/server architecture that allows you to access information on the Internet as if it were part of a seamless web. The goal of WWW is to make all online knowledge part of one interconnected web of documents and services, and allow you to follow facts and texts wherever they might lead. For systems with "character only" displays such as UNIX, DOS, and VMS, you have to use line browser software in which you move through the web by typing line numbers. On systems like Windows, X-Windows, NeXT, and Macs, there are client programs that allow you to make links by clicking and pointing. The client program MOSAIC available from the National Center for Supercomputing Applications (available for Windows, X- Windows, and Macs) is the recommended way of accessing the Web.
WHAT IS A CLIENT/SERVER ? The purpose of having computers communicate with each other in a client/server mode is that they can share in the work. In the old days, mainframes sent information out to dumb terminals, and the mainframe had to do all the work. In the client/server model, the serving machine can be either a microcomputer or a mainframe because microcomputers are so much more powerful than they used to be. The terms "client" and "server" refer to software that resides on machines throughout the Internet and this software is what makes it possible to use the Internet. Examples of client software are NCSA Telnet, Fetch (for the Mac), Gopher. Each of the clients just mentioned work in conjunction with server software specifically designed to provide the information sought by the client. For example, NCSA Telnet works in conjunction with a telnet server on another machine to make a remote connection to the server machine.