Business telephone systems are a range of telephone systems that have multiple lines. Business telephone systems are mostly used in business environments and range from small to large systems. A business telephone system is different from a normal telephone. It has additional features wherein multiple phones use multiple lines. Business Telephone Systems come in a wide range namely key systems, hybrid systems and private branch exchanges.
Using light buttons, a call operator can directly see and control incoming calls in a key system. The calls are directly routed to the location being called. Generally central office systems use the key system. Like line buttons on telephones, a key system is a manually operated switch.
Business telephone systems allow many features namely, answering machine functions, station specific, caller ID, automatic call accounting, selection of signaling sounds and remote supervision of the systems. Private branch exchanges have many features namely, internal switching network, switching and control cards, logic cards, power cards and related accessories, closets, cabinets and vaults, microcomputer or micro controller for control and logic and arbitrary data processing, switchboard or console to control incoming calls, interconnecting wiring and outside telco trunks; it delivers signals to the PBX.