1TCP/IP is a set of protocols developed to allow supporting computers to ration resources across a network. A community of researchers centered on the ARPAnet developed it. Certainly the best-known TCP/IP network is the ARPAnet. Starting with the basic definitions. The most accurate name for the set of protocols we are describing is the "Internet protocol suite". TCP and IP are two of the protocols in this suite. Because TCP and IP are the best known of the protocols, it has become common to use the term TCP/IP or IP/TCP to refer to the whole family. It is probably not worth fighting this habit. However this can lead to some oddities. For example, I find myself talking about NFS as being based on TCP/IP, even though it doesn't use TCP at all. (It does use IP. But it uses an alternative protocol, UDP, instead of TCP. All of the above terminologies will be talked about later in the report. TCP/IP is a family of protocols. A few contribute "low-level" functions required for many applications. These include IP, TCP, and UDP. Others are protocols for doing particular tasks, e.g. transferring files between computers, sending mail, or finding out who is logged in on another computer. Initially TCP/IP was used particularly between minicomputers or mainframes.