UTP Cables and RJ-45 Connectors

The UTP cabling used by popular Ethernet standards include either two or four pairs of wires. Because the wires inside the cable are thin and brittle, the cable itself has an outer jacket of flexible plastic to support the wires. Each individual copper wire also has a thin plastic coating to help prevent the wire from breaking. The plastic coating on each wire has a different color, making it easy to look at both ends of the cable and identify the ends of an individual wire.