The term resolution is the amount of information in a media asset measure by height and width in pixels. The more "pixels" the higher the quality of the picture.

Common Resolutions

CRT Televisions
 720 x 480
Older LCD Screens
1024 x 768
720p Screens (HD)
1280 x 720
1080o Screens (HD)
1920 x 1080

The number of pixels high relative to the number of pixels wide is the aspect ratio.