A host is loosely defined as any computer connected to a network that offers applications, services, functions or information resources to other nodes, hosts and devices on the network. A host server is a host that functions in systems using the client-server model of computing. A host can also serve as a node in a peer-to-peer context, in which it shares and consumes resources in equal fashion.

Unlike a server, which can be virtual, a host is a physical network node. At the same time, not all nodes are hosts; a network-connected device is only considered a host if it is assigned a host address, and typically only if it also functions as a general purpose computer, as opposed to a network printer or router, devices that are assigned IP addresses but that are not considered hosts.

Network computers that use the Internet Protocol Suite are often referred to as IP hosts, with computers functioning as part of the Internet called either Internet nodes or Internet hosts. IP and Internet hosts have network interfaces that are assigned one or more IP addresses, with the addresses being configured automatically upon start-up via the Dynamic Host Configuration Protocol (DHCP), structured manually by a network administrator, or obtained through some manner of stateless address auto-configuration method.