Peer-to-peer communication, the communications that travel from one user’s computer to another user’s computer without being stored for later access on a server. E-mail is not a P2P communication since it travels from the sender to a server, and is retrieved by the recipient from the server. On-line chat, however, is a P2P communication since messages travel directly from one user to another.
peer-to-peer (P2P) meaning in Information Science terminology / glossary / dictionary is:
File sharing between Internet users whose computers have been assigned IP addresses and are therefore capable of functioning as servers, a method of information exchange that became possible after 1996 when IP addresses were made available to PCs intermittently connected to the Internet. Unlike client-servernetworks in which certain computers are dedicated to serving others, workstations in a peer-to-peer network have equivalent capabilities. In the last decade of the twentieth century, P2P file sharing applications became the focus of litigation for facilitating the exchange of music protected by copyright. More recently, Internet service providers have tried to clamp down on P2P file sharing because of its high-bandwidth usage. Critics point out that P2P networking has legitimate uses, and some claim that throttling P2P file sharing is intended to direct users to client-server architecture, which allows content to be controlled more easily.