A network socket is an endpoint of a connection across computer networks. Nowadays, almost all communication between computers and distinct networks is based on the Internet Protocol, which uses sockets as a basis of communication. A socket is an abstract reference that a local program can pass to the network API to make use of a connection. Sockets are internally often represented in network programming APIs simply as integers, which identify which connection to use. In brief, we will be covering the following topics in this chapter:
The basics of sockets
The difference between TCP and UDP sockets
UDP sockets
TCP sockets
The Telnet program
A chat application