Gateway

1. A computer that sits between different networks or applications. The gateway converts information, data or other communications from one protocol or format to another. A router may perform some of the functions of a gateway. An Internet gateway can transfer communications between an enterprise network and the Internet. Because enterprises often use protocols on their local-area networks (LANs) that differ from those of the Internet, a gateway will often act as a protocol converter so that users can send and receive communications over the Internet.
2. A product or feature that uses proprietary techniques to link heterogeneous systems.