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 very closely linked with the invention and development of the telephone. Telephony is commonly referred to as the construction or operation of telephones and telephonic systems and as a system of telecommunications in which telephonic equipment is employed in the transmission of speech or other sounds between points, with or without the use of wires.

GPO telephone

This GPO telephone has an identifying mark on its base of 740 GEN 72/1. This identifier shows that the telephone was a model 740 telephone made by GEC-AEI Telecommunications, Newton Aycliffe, County Durham, in the first production run of 1972. The model 740 was first introduced in 1968 to replace the 710 model and was based on the 746 telephone. The 740 model was available in 3 standard colours, ivory, grey and black. Donated by SSE Group