Telephone

The telephone (from the Greek: τῆλε, tēle, "far" and φωνή, phōnē, "voice"), commonly referred to as a phone, is a telecommunications device that transmits and receives sound, most

A 1970's era AT&T "Touch-Tone" telephone
Inventor	Alexander Graham Bell
Launch year	1876
Available?	Worldwide

commonly the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to one another. It is one of the most common household appliances in the developed world, and has long been considered indispensable to business, industry and government. The word "telephone" has been adapted to many languages and is widely recognized around the world.

The device operates principally by converting sound waves into electrical signals, and electrical signals into sound waves. Such signals when conveyed through telephone networks — and often converted to electronic and/or optical signals — enable nearly every telephone user to communicate with nearly every other worldwide. Graphic symbols used to designate telephone service or phone-related information in print, signage, and other media include ℡(U+2121), ☎(U+260E), ☏(U+260F), and ✆(U+2706).