A thin-diameter wire (22 to 26 gauge) commonly used for telephone and network cabling. The wires are twisted around each other to minimize interference from other twisted pairs in the cable. Alexander Graham Bell invented this and was awarded a patent in 1881. Twisted pairs support less bandwidth than coaxial cable or optical fiber.
Unshielded (UTP) and Shielded (STP)
Twisted pair cables are available unshielded (UTP) or shielded (STP), with UTP being the most common. Shielded twisted pair (STP) is used in noisy environments and protects against electromagnetic interference.
Stranded and Solid
Both UTP and STP come in stranded and solid wire varieties. Stranded is the most common and also very flexible for bending around corners. Solid wire has less attenuation and spans longer distances but is less flexible.
Shielded and Unshielded Twisted Pairs
ScTP (screened twisted pair), also called "foil twisted pair" (FTP), uses one overall shield for more protection than UTP but not as much as STP, which has shields around each wire pair. For an actual example of STP vs. UTP, see cable categories
Cable Band- Data
# Type Width Rate
1 UTP Analog voice
2 UTP 1 Mbps
3 UTP/STP 16 MHz, 4 Mbps
4 UTP/STP 20 MHz, 16 Mbps
5 UTP/STP 100 MHz, 100 Mbps
5e UTP/STP 100 MHz, 1 Gbps
6 UTP/STP 200 MHz, 10 Gbps (<10 m)
6a UTP/STP 500 MHz, 10 Gbps (>10 m)
7 STP 600 MHz 10 Gbps
7a STP 1000 MHz 40 Gbps (<15 m)
The Real Twisted Pair