Origin of the concept

Historically the term host has also denoted a multi-user computer or software providing services to computer terminals, or a computer that provides services to smaller or less capable devices.

The term host is used in a number of RFCs that define the Internet and its predecessor ARPANET. The background is that while ARPANET was developed, computers connected to the network were typically main frame computer systems that could be accessed from dumb terminals connected via serial ports. Since the terminals did not reside software, they were not considered as hosts. The terminals were not connected to the network, and were not assigned any IP host address. Part of the picture is also that a vision behind the Internet is that it should facilitate distributed computing, where information as well as client and server software easily can be moved and shared among computers.