An Ethernet hub, active hub, network hub, repeater hub, multiport repeater, or simply hub is a network hardware device for connecting multiple Ethernet devices and making them act as a single network segment. Hubs are now largely obsolete, replaced by network switches except in ancient installations or specialized applications.

Computer Network Terms II

A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. The connections between nodes are established using either physically wired, optical, or wireless radio-frequency that may be arranged in various network topologies. The best-known computer network is the Internet.