The difference in having an HD (High Definition) or SD (Standard Definition) channel is the number of pixels contained in the image on display. In general this means HD gives you more details and a much finer picture than SD. There is a bit more to it but instead of boring you with details, we decided to show you! The image on the left side is of a TV displaying an HD channel and the image on the right is of a TV with a SD channel. You can see for yourself the difference in quality and clarity.