Television


Television
A television (also TV, telly or tube) is a device (pool) with a screen that receives broadcast signals and turns them into pictures and sound. The word "television" comes from the words "tele" (Greek for "far away") and "vision" ("seeing").
History of Television.
Usually a TV looks like a box. Older TVs had large wooden frames and sat on the floor like furniture. Newer TVs are much more varied. Some TVs can fit in your hand and run with batteries. Other TVs can take up a whole wall in a house, and may sit on the floor, or be just a large flat screen that can be mounted on the wall.
A television can show pictures from many places. At first, everyone used an antenna (or aerial). This would pick up shows from broadcast television stations. A TV station could be many miles away, and still be picked up. TVs can also show movies from VCD and DVD players or VCRs. Cable TV and Satellite TV can provide more programs at once than broadcast can. Video game consoles connect to TVs. Some computers can also use a TV as a monitor.
All TVs have screens where the picture is viewed. Before the 1970s these were usually "black and white", which made everything look grey. But now almost all TVs show colors. Screens also used to have rounded corners, but now they are usually mostly flat rectangles with straight edges. Before the 1990s, all TV screens had the same shape - they were a little bit wider than they were tall. For example, if a screen was 3 inches tall, it had to be 4 inches wide. Or if the screen was 30 cm tall, it had to be 40 cm wide. Now however, a new shape is becoming more popular. It is a wider rectangle that looks more like the shape of a movie theatre screen. This is called widescreen. If a widescreen set was 30 cm tall, it would be 53 cm 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.
All TVs used to be made with cathode ray tubes. These are like heavy glass jars with one side facing out to form the screen. Today there are also LCD, Plasma, Rear-Projection, and OLED (Organic Light Emitting Diode) TVs. Those kinds of TVs are better in many ways, but cathode ray tubes still cost less. Many people think that cathode ray tubes still show the best quality pictures, but the other kinds of screens are improving quickly.


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