3. Standard and HD television

The next step in the evolution of television is 'HD' or High Definition channels.

HD offers even higher quality pictures and sound than standard television.

Standard digital television uses 720 x 576 pixels on the screen. But High Definition uses much higher resolution of up to 1920 x 1080 pixels, more than five times as many pixels.

You will often see a television as being capable of '1080p' which means it can display the highest resolution images.

Both Blu-Ray disc players and some gaming machines can send HD quality pictures to the television.

There are also a number of HD television channels being broadcast via cable, satellite and terrestrial as well as over the internet.

Technology used

Screen technology changes fairly often. For example, the earlier digital televisions had a plasma flat screen. Then LED (Light Emitting Diode) technology started to dominate offering thinner, low power displays. Now OLED (Organic Light Emitting Diode) technology makes it possible to have a curved screen.

There are also 3D screens available, although they are less popular than 'normal' screens.