Television is a medium for communication that displays moving images. These images can be black and white or color and may be accompanied by sound. There are certain features that determine the different classifications of television sets. Some of them include: Television screen: The screen size of the television set is a major factor in determining its price. A regular TV is usually 4 units wide and 3 units high and a widescreen TV can be 16 units wide and 9 units high. Widescreen TV sets are usually more expensive, they are the type that can be found in cinema halls and produce images of very high quality. Most digital TV's today are widescreen. The format of movies being broadcasted is also changing from regular formats to a widescreen or digital format. Audio and video quality: Digital TV's usually have good sound quality. They have options of being connected to surround sound systems and usually come with at least one input and output terminal. Plasma and LCD TV's: Liquid crystal display (LCD) and plasma high definition are fast becoming the most popular technologies used to make television sets. These two types of TV's result in compact televisions, which product minimal heat. Plasma technology works by charging millions of small glass cells with neon and xenon, while LCD technology comprises of a liquid that is suspended between two panels that are transparent. These are then activated by voltage which allows light to pass through. LCD TV's display brighter images with higher contrast, while plasma TV's provide a higher color definition, better angles and sharper image movements. | 
