In computer networking, a network host, Internet host or host is a computer connected to the Internet. A network host can host information as well as client and/or server software.
Every Internet host has a unique IP address, including a host address part. The host address is assigned either manually by the computer administrator, or automatically at start-up by means of the Dynamic Host Configuration Protocol (DHCP).
Every host is a network node (i.e. a network device), but every node is not a host. Network nodes such as modems and network switches are not assigned host addresses, and are not considered as hosts. Devices such as network printers and hardware routers are assigned IP host addresses, but since they are not general-purpose computers, they are sometimes not considered as hosts in the literature.
Origin of the concept
The term terminal host denotes a multi-user computer or software providing services to computer terminals, or a computer that provides services to smaller or less capable devices. [1]
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.
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