High definition satellite TV is a broadcast format that provides a higher resolution picture than over-the-air (analog) broadcasts and regular digital broadcasts, resulting in a clearer, more colorful picture. Picture quality is measured in scan lines. The more scan lines a picture has, the clearer the picture. Analog TV has 525 scan lines per image, while HDTV has up to 1,080 lines per image - almost twice as many lines of resolution - giving you twice the clarity of analog TV.