Digital television uses a digital signal that is sent from a digital channel. This signal is condensed into a single program or multiple subchannels to allow for multibroadcasting of different programs. Digital television allows broadcasters to show their programs on three different resolution rates, which are 480, 720 and 1080, at 60 frames per second.
Channels broadcasting on either the 480 or 1080 resolution are sent in either progressive or interlaced video formats. A program in 480p, for example, has the full image updated every 60th of a second. A program broadcast in the interlace format has the image updated at the same amount of time.
Broadcasts made in 480p or 480i are formatted in the standard definition category. The resolution in SD, or secure digital, format is approximately equal to the picture quality of an analog TV broadcast. Programs shown in 720p, 1080p or 1080i fall under the high-definition category. Shows in HD have a higher resolution, which ranges from 1280 x 780 pixels to 1920 x 1080 pixels. This is a large jump when compared to an SD resolution of 704 x 480 pixels. Digital television shows in the HD format also have a larger aspect ratio of 16:9.