Since you are working most of the time in a resolution of 640 x 480 pixels on your computer monitor, you should understand the concepts of underscan and overscan. Your computer monitor displays a full picture. When you convert the picture to video, a video monitor or TV will crop the outside edges of the picture. Video monitors and TVs display the picture in overscan mode; only professional video monitors can be set to show underscan, which shows all of the displayed information.
