Coaxial cable or coax is an electrical cable consisting of an inner conductor surrounded by a concentric conducting shield, with the two separated by a dielectric (insulating material); many coaxial cables also have a protective outer sheath or jacket. The term "coaxial" refers to the inner conductor and the outer shield sharing a geometric axis.

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.