The telephone is the terminal equipment for voice communication in the telephone network. The telephone or the telephone set is a telecommunication device consisting of a speech capsule and a listening capsule, which are usually housed in the handset and form a fixed unit, and the dialing device, which used to be a dial plate and is now a dialkeypad, a membrane keypad or a touch screen.
In standard telephones, replacing the handset is directly coupled with the on/off function. In addition, a telephone includes a number switch or the dial pad for dialing numbers, some keys for special functions, others for service functions.
Telephones have various features and functional units that support voice communication. These include the loudspeaker and the microphone for handsfree talking, as well as a display for multiline displays, a dial keypad, dialog keys for selecting services and, of course, freely assignable keys for number storage.