Twisted pair is the ordinary copper wire that connects home and many business computers to the telephone company. To reduce crosstalk or electromagnetic induction between pairs of wires, two insulated copper wires are twisted around each other. Each signal on twisted pair requires both wires. Since some telephone sets or desktop locations require multiple connections, twisted pair is sometimes installed in two or more pairs, all within a single cable. For some business locations, twisted pair is enclosed in a shield that functions as a ground.
Twisted pair comes with each pair uniquely color coded when it is packaged in multiple pairs.
Different uses such as analog , digital , and Ethernet require different pair multiples. Although twisted pair is often associated with home use, a higher grade of twisted pair is often used for horizontal wiring in LAN installations because it is less expensive than coaxial cable . The wire you buy at a local hardware store for extensions from your phone or computer modem to a wall jack is not twisted pair.