In telecommunications, telephony ( ) encompasses the general use of equipment to provide communication over distances, specifically by connecting telephones to each other. The technology is associated with the electronic transmission of voice, fax, or other information between distant parties using systems historically associated with the telephone, a hand-held device containing both a speaker or transmitter and a receiver. It is commonly referred to as the construction or operation of telephones or telephonic systems and as a system of telecommunications in which telephonic equipment is employed in the transmission of speech or other sound between points, with or without the use of wires.

Die Telefonie (griechisch τηλεφωνία, von τηλε-, altgr. Aussprache tele-, „fern“, „weit“ und φωνή, altgr. Aussprache phoné, „Stimme“) bezeichnet in erster Linie die Sprachkommunikation über eine technische Vorrichtung (z. B. Telefonnetz). Der erste Forscher, dem diese Form der Übermittlung von Sprachdaten bereits 1860 gelang, war Philipp Reis (verkannt und verarmt gestorben am 14. Januar 1874).

La téléphonie est un système de télécommunication qui a pour but la transmission de son et en particulier la transmission de la parole.

• Sistema de transmissão de vozes a distância via cabos, fios ou ondas hertzianas.