Different uses such as analog, digital, and Ethernet require different pair multiples. Twisted pair comes with each pair uniquely color coded when it is packaged in multiple pairs. Twisted pair is now frequently installed with two pairs to the home, with the extra pair making it possible for you to add another line (perhaps for modem use) when you need it. Ordinary wire to the home is unshielded twisted pair (UTP). This is known as shielded twisted pair (STP). For some business locations, twisted pair is enclosed in a shield that functions as a ground. 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. Each connection on twisted pair requires both wires. To reduce crosstalk or electromagnetic induction between pairs of wires, two insulated copper wires are twisted around each other. 2Twisted pair is the ordinary copper wire that connects home and many business computers to the telephone company.
