P2P是Peer-to-Peer的缩写，也叫对等互联或点对点技术。与TCP、UDP不同，P2P并不是一种新的协议，而是利用现有的网络协议实现网络数据或资源信息共享的技术，它使用的可能是TCP，也可能是UDP或者其它协议。使用P2P技术，可以让一台计算机与另一台计算机直接交换数据，通过Internet直接使用对方的文件，而不必像传统的C/S模式全部通过服务器处理。(P2P is the abbreviation of Peer-to-Peer, also called peer to peer or peer to peer technology. Unlike TCP and UDP, P2P is not a new protocol, but a technology that uses existing network protocols to realize network data or resource information sharing. It may use TCP, or UDP or other protocols. The use of P2P technology allows one computer to exchange data directly with another computer and directly use the other's files through Internet, without having to deal with the server all through the traditional C/S mode.)