The basic analog telecommunications service provided by a local telco. Plain Old Telephone Service (POTS) was the only type of telephone service until the 1970s.
Starting from your home or customer premises, two-pair copper twisted-pair wire runs to your local telco’s central office (CO). This copper wire connection forms what is known as the local loop. The CO has switches that connect you to another local subscriber, to another CO, or to a long-distance provider, depending on whether your call is local or long distance. POTS is an inexpensive circuit-switched telecommunications service, but it supports data transfer speeds up to only 56 Kbps. It typically takes 15 to 30 seconds to establish connections for data transfer using modems.