Resolution is a measure of the number of pixels or "dots" that are displayed on the screen you are viewing, for example a resolution of 1280x1024 means that there is a grid of pixels on the screen 1280 horizontally and 1024 vertically, each dot displaying a different colour. Definition is a measure of how often these dots change their colour, standard televisions change each of the dots colour either 50 or 100 times a second, where as a high definition television might change these dots 720 or 1080 a second.