Three main types of network cables are used in communication systems: fiber optic cable, twisted pair cable, and coaxial cable. Fiber optic cable uses glass or plastic strands to transmit data using light signals and comes in single mode, multi-mode, or plastic optical fiber varieties. Twisted pair cable consists of two copper wires twisted together to reduce interference and comes as either unshielded or shielded twisted pair. Coaxial cable contains a copper wire within an insulated tube surrounded by a shield and is used to transmit radio frequency signals like cable TV.