Historically, all TVs made using a cathode ray tube (CRT). They were produced like this when TVs were first created and continued to be so until the 1990′s. A CRT television worked by having a rear end which consisted of a negative charged filament, which then fires electrons out into the vacuum. The next phase of the process is very complicated so it’s best not to go into too much details, but broadly speaking the electrons then hit the phosphor coated screen of the monitor or television and a picture is created.

This entire process is conducted in a glass tube which is why CRT monitors were so large and bulky.

After CRT televisions we had liquid crystal display (LCD) tvs which use a completely different technology to create a picture. LCD TVs use fluorescent back lighting lamps to illuminate a image onto the TV screen.
These fluorescent lamps cannot be turned off individually so are constantly turned on which means that when your TV displays black it can sometimes appear greyish.

LED technology is completely different again and so far seems to be the most complete system. It uses lots of LED backlights to illuminate the screen from behind. These LED backlights can be individually turned on and off. This allows LED TVs to display blacks much better as they can turn the LEDs off completely rather than keeping them on as with LCD TVs.

By turning individual lights out when they are not required it is estimated that a LED TV will use up to 70% less energy than a equivalent size LCD TV. This benefits both the environment and your pocket.

LED TVs are much slimmer than LCD TVs due to the small space required by the LED backlights. Some models such as the Samsung 7 Series TVs is only 29.9mm deep.