CAT5, or Category 5, is a type of twisted pair cable used for networking and telecommunications. It supports data transmission speeds of up to 100 Mbps and is commonly used in local area networks (LANs). The cable consists of four pairs of wires, which help reduce interference and improve signal quality. Introduced in the 1990s, CAT5 cables are often used to connect computers, routers, and switches. While newer standards like CAT5e and CAT6 offer higher speeds and better performance, CAT5 remains a cost-effective option for basic networking needs.