Telephonewikipedia
A telephone, or phone, is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be heard directly.
telephonephonetelephonesLocal Telephone Servicefixed telephonyphonestelephonyTelephone numberFixed-Line Telephonytelephone receiver

Alexander Graham Bell

Alexander Graham BellBellGraham Bell
In 1876, Scottish emigrant Alexander Graham Bell was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice.
Alexander Graham Bell (March 3, 1847 – August 2, 1922) was a Scottish-born scientist, inventor, engineer, and innovator who is credited with inventing and patenting the first practical telephone.

Microphone

microphonemicrophonescondenser microphone
The essential elements of a telephone are a microphone (transmitter) to speak into and an earphone (receiver) which reproduces the voice in a distant location.
Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public events, motion picture production, live and recorded audio engineering, sound recording, two-way radios, megaphones, radio and television broadcasting, and in computers for recording voice, speech recognition, VoIP, and for non-acoustic purposes such as ultrasonic sensors or knock sensors.

Rotary dial

rotary dialdialrotary telephone
Until approximately the 1970s, most telephones used a rotary dial, which was superseded by the modern dual-tone multi-frequency (DTMF) push-button dial, first introduced to the public by AT&T in 1963. Until the 1960s dials used almost exclusively the rotary technology, which was replaced by dual-tone multi-frequency signaling (DTMF) with pushbutton telephones (A4).
A rotary dial is a component of a telephone or a telephone switchboard that implements a signaling technology in telecommunications known as pulse dialing.

AT&T

AT&TAT&T Inc.SBC
Until approximately the 1970s, most telephones used a rotary dial, which was superseded by the modern dual-tone multi-frequency (DTMF) push-button dial, first introduced to the public by AT&T in 1963.
It is the world's largest telecommunications company, the second largest provider of mobile telephone services, and the largest provider of fixed telephone services in the United States through AT&T Communications.

Mobile phone

mobile phonecell phonemobile
Hand-held mobile phones were introduced for personal service starting in 1973.
A mobile phone, known as a cell phone in North America, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area.

Telecommunication

telecommunicationstelecommunicationcommunications
A telephone, or phone, is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be heard directly.
20th and 21st century technologies for long-distance communication usually involve electrical and electromagnetic technologies, such as telegraph, telephone, and teleprinter, networks, radio, microwave transmission, fiber optics, and communications satellites.

Dual-tone multi-frequency signaling

DTMFtouch-tonetouch tone
Until approximately the 1970s, most telephones used a rotary dial, which was superseded by the modern dual-tone multi-frequency (DTMF) push-button dial, first introduced to the public by AT&T in 1963. Until the 1960s dials used almost exclusively the rotary technology, which was replaced by dual-tone multi-frequency signaling (DTMF) with pushbutton telephones (A4).
Dual-tone multi-frequency signaling (DTMF) is an in-band telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers.

Duplex (telecommunications)

full-duplexhalf-duplexduplex
Telephones are duplex devices, meaning they permit transmission in both directions simultaneously.
An example of a full-duplex device is a telephone; the parties at both ends of a call can speak and be heard by the other party simultaneously.

Landline

landlinefixed linefixed-line
This gave rise to landline telephone service in which each telephone is connected by a pair of dedicated wires to a local central office switching system, which developed into fully automated systems starting in the early 1900s. A traditional landline telephone system, also known as plain old telephone service (POTS), commonly carries both control and audio signals on the same twisted pair (C in diagram) of insulated wires, the telephone line.
A landline telephone (also known as land line, land-line, main line, home phone, landline, fixed-line, and wireline) is a phone that uses a metal wire or optical fiber telephone line for transmission as distinguished from a mobile cellular line, which uses radio waves for transmission.

Videotelephony

videoconferencingvideo conferencingvideo chat
They may be able to record spoken messages, send and receive text messages, take and display photographs or video, play music or games, surf the Internet, do road navigation or immerse the user in virtual reality.
A videophone is a telephone with a video display, capable of simultaneous video and audio for communication between people in real-time.

Telephone switchboard

switchboardtelephone switchboardswitchboards
Being impractical beyond just a few customers, these systems were quickly replaced by manually operated centrally located switchboards.
A telephone switchboard is a telecommunications system used in the public switched telephone network or in enterprises to interconnect circuits of telephones to establish telephone calls between the subscribers or users, or between other exchanges.

Handset

handsettelephone handsethandset receiver
The receiver and transmitter are usually built into a handset which is held up to the ear and mouth during conversation.
A handset is a component of a telephone that a user holds to the ear and mouth to receive audio through the receiver and speak to the remote party via the built-in transmitter.

Telephone number

telephone numberphone numbertelephone numbers
In addition, most telephones contain a ringer, which produces a sound to announce an incoming telephone call, and a dial or keypad used to enter a telephone number when initiating a call to another telephone.
In addition to telephones, they have been used to access other devices, such as computer modems, pagers, and fax machines.

Push-button telephone

push-button telephonepush-button dialingpushbutton telephones
Until the 1960s dials used almost exclusively the rotary technology, which was replaced by dual-tone multi-frequency signaling (DTMF) with pushbutton telephones (A4).
The push-button telephone is a telephone that has buttons or keys for dialing a telephone number, in contrast to having a rotary dial as in earlier telephone instruments.

Plain old telephone service

POTSplain old telephone serviceLocal Telephone Service
A traditional landline telephone system, also known as plain old telephone service (POTS), commonly carries both control and audio signals on the same twisted pair (C in diagram) of insulated wires, the telephone line.
Plain old telephone service (POTS), or plain ordinary telephone service, is a retronym for voice-grade telephone service employing analog signal transmission over copper loops.

Loudspeaker

loudspeakerspeakerloudspeakers
The transmitter converts the sound waves to electrical signals which are sent through a telephone network to the receiving telephone, which converts the signals into audible sound in the receiver or sometimes a loudspeaker.
Johann Philipp Reis installed an electric loudspeaker in his telephone in 1861; it was capable of reproducing clear tones, but also could reproduce muffled speech after a few revisions.

Smartphone

smartphonesmartphonessmart phone
Since 1999, the trend for mobile phones is smartphones that integrate all mobile communication and computing needs.
Today, smartphones largely fulfil their users' needs for a microphone (smartphones often have one to four microphones), a digital camera (most smartphones are made with one front-facing and one to three rear-facing integrated digital cameras), a communications device (smartphones can transmit online chat, e-mails, telephone calls and video chat through the Internet by Wi-Fi as well as mobile broadband; a smartphone uses its camera in video chat, as well as its microphone in video chat and telephone calls), a handheld audio recorder (using the microphone), a satellite navigation system and trip planner, weather forecasting, a media player, a clock, news, a calculator, a web browser, a video game player, a flashlight (smartphones may possess one to two LEDs for illumination and photographic flash needs), a compass (smartphones that contain built-in magnetometers are able to function as a compass), an address book, a note creator, an event calendar, etc. Some apps allow sending and receiving facsimile (fax) over a smartphone, including raster facsimile data generated directly and digitally from document and image file formats.

Ringing (telephony)

ringingmagenta boxringing signal
If the called party's line is available, the exchange sends an intermittent ringing signal (about 75 volts alternating current (AC) in North America and UK and 60 volts in Germany) to alert the called party to an incoming call.
Ringing is a telecommunication signal that causes a bell or other device to alert a telephone subscriber to an incoming telephone call.

Communications satellite

communications satellitesatellitesatellite communications
Satellite technology may be used for communication over very long distances.
Communications satellites are used for television, telephone, radio, internet, and military applications.

Signal

signalsignalselectrical signal
The transmitter converts the sound waves to electrical signals which are sent through a telephone network to the receiving telephone, which converts the signals into audible sound in the receiver or sometimes a loudspeaker.
For example, the words "Mary had a little lamb" might be the message spoken into a telephone.

Twisted pair

twisted pairtwisted-pairunshielded twisted pair
A traditional landline telephone system, also known as plain old telephone service (POTS), commonly carries both control and audio signals on the same twisted pair (C in diagram) of insulated wires, the telephone line.
UTP is the primary wire type for telephone usage and is very common for computer networking.

Lineman's handset

lineman's handsettest set
A lineman's handset is a telephone designed for testing the telephone network, and may be attached directly to aerial lines and other infrastructure components.
A lineman's handset is a special type of telephone used by technicians for installing and testing local loop telephone lines.

Johann Philipp Reis

Johann-Philipp-Reis AwardReis, PhilippReis, Johann Philipp
Later, c. 1860, Johann Philipp Reis used the term in reference to his Reis telephone, his device appears to be the first such device based on conversion of sound into electrical impulses, the term telephone was adopted into the vocabulary of many languages.
In 1861, he constructed the first make-and-break telephone, today called the Reis telephone.

Speakerphone

speakerphonespeaker
In most landline telephones, the transmitter and receiver (microphone and speaker) are located in the handset, although in a speakerphone these components may be located in the base or in a separate enclosure.
A speakerphone is a telephone with a microphone and loudspeaker provided separately from those in the handset.

On- and Off-hook

off-hookon-hookon hook
The landline telephone contains a switchhook (A4) and an alerting device, usually a ringer (A7), that remains connected to the phone line whenever the phone is "on hook" (i.e. the switch (A4) is open), and other components which are connected when the phone is "off hook".