Editing Telephony Application Programming Interface (section)

{{Short description|Microsoft Windows API}}
The '''Telephony Application Programming Interface''' ('''TAPI''') is a [[Microsoft Windows]] [[Application programming interface|API]], which provides [[computer telephony integration]] and enables [[personal computer|PC]]s running [[Microsoft Windows]] to use [[telephone]] services. Different versions of TAPI are available on different versions of Windows. TAPI allows applications to control telephony functions between a computer and telephone network for data, fax, and voice calls. It includes basic functions, such as dialing, answering, and hanging up a call. It also supports supplementary functions, such as hold, transfer, conference, and call park found in [[Private branch exchange|PBX]], [[ISDN]], and other telephone systems. 

TAPI is used primarily to control either modems or, more recently, to control business telephone system (PBX) handsets. When controlling a [[Private branch exchange|PBX]] handset, the driver is provided by the manufacturer of the telephone system. Some manufacturers provide drivers that allow the control of multiple handsets. This is traditionally called "third-party control". Other manufacturers provide drivers that allow the control of a single handset. This is called "first-party control". Third-party drivers are designed to allow applications to see and/or control multiple extensions at the same time. Some telephone systems only permit one third-party connection at a time. First-party drivers are designed to allow applications to monitor and/or control one extension at a time. Telephone systems naturally permit many of these connections simultaneously.  Modem connections are by nature first-party.

TAPI can also be used to control voice-enabled telephony devices, including voice modems and dedicated hardware such as [[Dialogic Corporation|Dialogic]] cards.