Gateway

A device that is used to interface two otherwise incompatible network facilities. Also a term used in networking. It is a computer providing a connection between two networks, two E-mail handling systems, or a Usenet newsgroup and a mailing list. A gateway reformats the data so that it will be acceptable to the system it is passing into. A shared connection between a local area network and a larger system, such as a Mainframe computer or a large packet switching network, whose communications protocols are different. Usually slower than a bridge or a router, a gateway is a combination of hardware and software with its own processor and memory used to perform protocol conversions.