"This is a very brief introduction to IP networking. For more in-depth information, there are a number of excellent references. In particular, Douglas Comer's Internetworking with TCP/IP (Prentice Hall) is one of the standard references and provides a wealth of information on the subject. If a device wants to communicate using TCP/IP, it needs an IP address. When the device has an IP address and the appropriate software and hardware, it can send and receive IP packets. Any device that can send and receive IP packets is called an IP host"