Power-line communication (also known as power-line carrier or PLC) carries data on a conductor used simultaneously for AC electric power transmission or electric power distribution to consumers. Power-line communications systems operate by adding a modulated carrier signal to the wiring system. Different types of power-line communications use different frequency bands.

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.