The way that a television works is different depending on the type of television being used. There are three major existing technologies for televisions are cathode ray tubes, plasma televisions and liquid crystal displays (LCD). Each type of television operates drastically differently from the next.
Cathode ray tubes stimulate phosphorescent chemicals in the screen with beams of ions. These televisions are both heavy and inefficient at larger sizes.
Plasma televisions are a much more modern type of television and have a much thinner profile than the long tube required by cathode ray tubes. Their screens are composed of many tiny cells filled with noble gases which are electrified and give off energy to light up phosphorescent chemicals in the screen. There is done digitally in immediate proximity to the phosphors, therefore, no long tube or ion beam is required.
Liquid crystal displays use a light behind the screen to illuminate their images, while each liquid crystal cell controls light filters that control the color of the outgoing light. They are often even thinner than plasma screens.
The pricing for different types of televisions varies based on what technology is used. Modern models, like the plasma or LCD are more expensive than a cathode ray tube model. All varieties of televisions can be found in electronics and appliance retailers.