The telephone, or phone, is a telecommunications device that transmits and receives sounds, usually 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 each other. Developed in the mid-1870s by Alexander Graham Bell and others, the telephone has long been considered indispensable to businesses, households and governments, is now one of the most common appliances in the developed world. The word "telephone" has been adapted to many languages and is now recognized around the world.
All modern telephones have a microphone to speak into, an earphone (or 'speaker') which reproduces the voice of the other person, a ringer which makes a sound to alert the owner when a call is coming in, and a keypad (or on older phones a telephone dial) to enter the telephone number of the telephone to be called. The microphone and earphone are usually built into a handset which is held up to the face to talk. The keypad may be part of the handset or of a base unit to which the handset would be connected. A landline telephone is connected by a pair of wires to the telephone network, while a mobile phone (also called a cell phone) is portable and communicates with the telephone network by radio. A cordless telephone has a portable handset which communicates by radio transmission with the handset owners base station which is connected by wire to the telephone network, and can only be used within about 50 feet from the base station.
The microphone converts the sound waves to electrical signals and then these are sent through the telephone network to the other phone and there converted by an earphone, or speaker, back into sound waves. Telephones are a duplex communications medium, meaning they allow the people on both ends to talk simultaneously. The telephone network, consisting of a worldwide net of telephone lines, fiberoptic cables, microwave transmission, cellular networks, communications satellites, and undersea telephone cables connected by switching centers, allows any telephone in the world to communicate with any other. Each telephone line has an identifying number called its telephone number. To initiate a telephone call the user enters the other telephone's number into a numeric keypad on the phone. 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).
Although originally designed for simple voice communications, most modern telephones have many additional capabilities. They may be able to record spoken messages, send and receive text messages, take and display photographs or video, play music, and surf the Internet. A current trend is phones that integrate all mobile communication and computing needs; these are called smartphones.
Read more about Telephone: History, Basic Principles, Details of Operation, Digital Telephony, IP Telephony, Usage, Telephone Operating Companies, Patents
Other articles related to "telephone":
... The Bell Telephone Hour (also known as The Telephone Hour) is a long-run concert series which began April 29, 1940 on NBC Radio and was heard on NBC until June 30, 1958 ... Sponsored by Bell Telephone as the name assumes, it showcased the best in classical and Broadway music, reaching eight to nine million listeners each week ...
... to as RJ9, RJ10, and RJ22) 6P2C for RJ11 single telephone line 6P4C for RJ14 two telephone lines 6P6C for RJ25 three telephone lines 8P8C for RJ61X ...
... US 174,465 -- Telegraphy (Bell's first telephone patent) -- Alexander Graham Bell US 186,787 -- Electric Telegraphy (permanent magnet receiver) -- Alexander ... System—Amos Edward Joel (Bell Labs) US 3,906,166 -- Radio Telephone System (DynaTAC cell phone) -- Martin Cooper et al ...
... List of Canadian telephone companies Australia Telstra, Optus, Vodafone, Hutchison Telecom(3G network), AAPT, Primus Telecom, Nextgen Networks, Agile Communications, TransACT People ...
... NBTel was founded as the New Brunswick Telephone Company in 1888 after Bell Telephone Company of Canada's attempt to establish telephone service in the Maritime provinces failed ... In 1973, NBTel purchased the last independent telephone operator in New Brunswick, giving it a monopoly for the telephone service ...
Famous quotes containing the word telephone:
“The press and politicians. A delicate relationship. Too close, and danger ensues. Too far apart and democracy itself cannot function without the essential exchange of information. Creative leaks, a discreet lunch, interchange in the Lobby, the art of the unattributable telephone call, late at night.”
—Howard Brenton (b. 1942)
“Men will not give up their privilege of helplessness without a struggle. The average man has a carefully cultivated ignorance about household matters—from what to do with the crumbs to the grocer’s telephone number—a sort of cheerful inefficiency which protects him better than the reputation for having a violent temper.”
—Crystal Eastman (1881–1928)
“Language is as real, as tangible, in our lives as streets, pipelines, telephone switchboards, microwaves, radioactivity, cloning laboratories, nuclear power stations.”
—Adrienne Rich (b. 1929)