A telecommunication medium used for sending moving pictures in monochrome (black and white), colour, and two or three dimensions, as well as sound, is referred to as television (abbreviated as TV or telly). The phrase "television set" may refer to a television set, a television programme, or the medium through which television is broadcasted. Marketing, entertainment, news, and sports are all broadcast on television, which is a mass media.
In 2013, a television set was in the possession of 79 percent of the world's households. In the late 1990s, the replacement of earlier bulky, high-voltage vacuum tube (CRT) screen displays with compact, power flat-panel alternative technologies such as LCDs (both fluorescent-backlit and LED), OLED displays, and plasma displays was the beginning of a hardware revolution that began with computer monitors and continued with OLED displays and plasma displays. The vast majority of television sets sold in the 2000s were flat-panel, with the majority of them being LEDs. Major manufacturers stated that they will phase out CRT, DLP, plasma, and even fluorescent-backlit LCD displays by the middle of the decade. The use of OLEDs is anticipated to progressively phase out the use of LEDs in the not-too-distant future. In addition, prominent manufacturers have said that they would increase their production of smart televisions starting in the mid-2010s. By the late 2010s, smart TVs with built-in Internet and Web 2.0 features had surpassed traditional television as the main source of entertainment.
Television signals were originally delivered exclusively as terrestrial television, with high-powered radio-frequency television transmitters broadcasting the signal to individual television receivers. Television signals were prepared and distributed only as terrestrial television. As an alternative, television signals are delivered via coaxial cable or optical fibre, satellite systems, and, more recently, the Internet. This kind of transmission was sent as analogue signals until the early 2000s, but a shift to digital television was anticipated to be completed across the globe by the late 2010s. A typical television set is composed of a number of internal electrical circuits, one of which is a tuner, which is responsible for receiving and decoding broadcast signals. Rather than television, the term video monitor should be used to describe a visual display device that does not have a tuner.