Television (TV) is a widely used telecommunication medium for transmitting and receiving moving images, either monochromatic ("black and white") or color, usually accompanied by sound. "Television" may also refer specifically to a television set, television programming or television transmission. The word is derived from mixed Latin and Greek roots, meaning "far sight": Greek tele (τῆλε), far, and Latin visio, sight (from video, vis- to see, or to view in the first person).

Commercially available since the late 1930s, the television set has become common in homes, businesses and institutions, particularly as a source of entertainment and news. Since the 1970s the availability of video cassettes, laserdiscs, DVDs and now Blu-ray Discs, have resulted in the television set frequently being used for viewing recorded as well as broadcast material.

Although other forms such as closed-circuit television (CCTV) are in use, the most common usage of the medium is for broadcast television, which was modeled on the existing radio broadcasting systems developed in the 1920s, and uses high-powered radio-frequency transmitters to broadcast the television signal to individual TV receivers.

Broadcast TV is typically disseminated via radio transmissions on designated channels in the 54–890 megahertz frequency band. Signals are now often transmitted with stereo and/or surround sound in many countries. Until the 2000s broadcast TV programs were generally recorded and transmitted as an analog signal, but in recent years public and commercial broadcasters have been progressively introducing digital television broadcasting technology.

A standard television set comprises multiple internal electronic circuits, including those for receiving and decoding broadcast signals. A visual display device which lacks a tuner is properly called a monitor, rather than a television. A television system may use different technical standards such as digital television (DTV) and high-definition television (HDTV). Television systems are also used for surveillance, industrial process control, and guiding of weapons, in places where direct observation is difficult or dangerous.

Amateur television (ham TV or ATV) is also used for experimentation, pleasure and public service events by amateur radio operators. Ham TV stations were on the air in many cities before commercial TV stations came on the air.

Quotes regarding Television

Sourced

Arranged by author

• The role of television is the illusion of company, noise. I call it the fifth wall and the second window: the window of illusion.
  • Mumia Abu-Jamal I spend my days preparing for life, not for death The Guardian, Laura Smith 25 October 2007 [1]

• The luminous screen in the home carries fantastic authority. Viewers everywhere tend to accept it as a window on the world... It has tended to displace or overwhelm other influences such as newspapers, school, church, grandpa, grandma. It has become the definer and transmitter of society's values.
  • Erik Barnouw, The Sponsor: Notes On a Modern Potentate (Oxford University Press, 1978), ISBN 0-19-502614-4, p. 75

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Thu Jul 29 10:51:09 2010