Ok, so here’s the simple answer. Standard-definition television or SDTV refers to television systems that have a resolution that meets standards but not considered either enhanced definition or high definition.

SD TV usually is used in position to digital TV in particular when broadcasting at the same resolution as analog TV. What is analog TV?

In ATSC, SDTV can be broadcast in 704 pixels × 480 lines with 16:9 ratio (40:33 rectangular pixel), 704 pixels × 480 lines with 4:3 aspect ratio (10:11 rectangular pixel) or 640 pixels × 480 lines with 4:3 ratio (and square pixels). The refresh rate fan be any of 24, 30 or 60 frames per second.

Confusing I know, but SD TV is basically not as high quality as HD TV.

Digital SDTV in 4:3 aspect ratios has the same outer shell as the regular analog TV without the ghosting, snowy images and static noises. However, if the reaction or the reception is deprived, you may come across various other artifacts such as stuttering.

Alright, so when resolution is considered, both the resolution of the transmitted signal and the displayed resolution of a TV set are taken into account.

Lots of fancy names and numbers but like I said earlier, SD TV is not as high quality as HD TV. What is High Definition TV?