Atelevision set (also known as atelevision receiver ortelevisor or simply atelevision,TV set,TV receiver orTV) is amachine with ascreen or set oflenses. Televisions receivebroadcastingsignals and change them intopictures andsound. The word "television" comes from the wordstele (Greek forfar away) andvision (sight).
Sometimes a television can look like abox. Older TVs had a largecathode ray tube in a large wooden frame and sat on the floor likefurniture. Newer TVs are much lighter and flatter.
The television was invented in the 1920s but the equipment was expensive and the pictures were poor. By the 1950s, these problems had been fixed and TVs became widespread.
All TVs have screens where the picture is viewed. Before the 1950s these were usually "black and white", which made everything look grey, but all modern TVs show colors. Most 20th century screens also had rounded corners. That is because television screens werecathode ray tubes. These are like heavy glass jars with one side bulging out to form the screen.
Todayflat panel displays are the usual kind. These are usually flat rectangles with straight edges. This long rectangle looks more like the shape of amovie theatre screen. This is calledwidescreen. If a widescreen set was 30cm tall, it would be 53cm wide. For this to work best, TV shows also need to be made in widescreen. Widescreen sets can still be any size, but they have the same widescreen shape.
