1 [computing] In a computer network, the computer that contains data being accessed by other computers.
2 [computing] A computer connected to a TCP/IP network such as the Internet. Each host has a unique IP address.
3 [ESRI software] In ArcIMS, the combination of the ArcIMS user interface (Author, Designer, and Administrator, and Service Administrator), the Application Server Connectors, and the ArcIMS Application Server.