The Blanket pattern - A blanketed horse displays a base coloured coat, with a white area extending over the quarters and barrel to varying degrees.  The white area may or may not have spots.  Some horses display a "frosting" of white over their quarters, looking rather like lacework.  This is known as a "lace blanket."  The stallion at the top displays a large spotted blanket, while the foal below displays a lace blanket.  Some times a blanket can go right up a horse's neck, but leaving their  legs dark.  This is also called "near leopard" or "3/4 leopard."  My horse Nevada was born a bay with a spotted blanket, but has roaned out to near leopard.

The Leopard pattern - A leopard Appaloosa displays a white body with base-coloured spots.  It may have varnish marks (patches of dilute base colour) in various areas, most commonly around elbows, shoulders and neck.  The stallion to the right is a leopard, my horse Joe, below him, is also a leopard but with considerable varnish marks, and there is also a variation known as a "fewspot."  These are leopard Appaloosas with little or no spots whatsoever.  When bred they produce coloured foals almost 100% of the time.