Telephony is the field of technology involving the development, application, and deployment of telecommunication services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is intimately linked to the invention and development of the telephone.
A commercial IP telephone, with keypad, control keys, and screen functions to perform configuration and user features.
A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals that are transmitted via cables and other communication channels to another telephone which reproduces the sound to the receiving user. The term is derived from Greek: τῆλε and φωνή, together meaning distant voice. A common short form of the term is phone, which came into use early in the telephone's history.
An old rotary dial telephone
AT&T push button telephone made by Western Electric, model 2500 DMG black, 1980
Alexander Graham Bell's Telephone Patent Drawing
Replica of the telettrofono, invented by Antonio Meucci and credited by several sources as the first telephone.
