From the Glossary:

LCD or Liquid Crystal Displays
Technology with high quality images and slim designs mostly used in digital watches and laptop monitors.

Plasma
Gas used to light the many bulbs in plasma screens. This gas is made up of equal numbers of free electrons and positive ions in approximate equal numbers.

Resolution
The size of the images seen on computer displays and other TV screens. The higher the resolution, the better the picture quality and clarity of the images.

Widescreen
Displays which let you view at a ratio similar to that in the cinema, 16:9, whereas standard TVs only offer a 4:3. view.