On the Internet, the term "host" means any computer that has full two-way access to other computers on the Internet. A host has a specific "local or host number" that, together with the network number, forms its unique IP address.

If you use Point-to-Point Protocol (PPP) to get access to your access provider, you have a unique IP Address for the duration of any connection you make to the Internet and your computer is a host for that period. In this context, a "host" is a node in a network.

The term generally means a device or program that provides services to some smaller or less capable device or program.