Coaxial cable 

Coaxial cable (often ‘coax’) offers high-data rates and high immunity to electrical interference. It is used to connect data and communication devices. It consists of (1) an inner wire surrounded by (2) a layer of insulating material, then (3) a concentric layer of conductive material, then (4) an outer cover. The conductive material (3) shields the wire (1) from interference.