Networks - Physical Connections
Electrical Cables - Twisted pair cables

Twisted pair cables come in two types, either as an unshielded twisted pair (UTP) which is common in telephone cables, or as a shielded twisted pair (STP).

Unshielded twisted pair cables have pairs of insulated copper wires twisted round each other to cancel out electromagnetic interference.

Shielded twisted pair wires have a metal sheath encasing the twisted pairs, shielding them further from outside electromagnetic interference.