There are a range of markings on the horses face but the most common ones are:
1) Star: When a horse/pony has got a little circle mark on the top of the head and can only been seen if you lift up the horses forelock(the horses fringe)
A snip is simply a marking on a horses muzzle or nose
Dapple is not a color but a marking. Dapples can appear on any colored horse though they are most common on grey horses and are usually considered a sign of good health.
Gypsy Vanner's can come in all equine colors, with black and white pinto the most common color and marking.
the quarterhorse is the most common
brown is the most common.
The American Quarter Horse
the american quarter horse
American quarter horse and paint/pinto there are also many more, but these are two of the most common
It has no meaning, no special symbolism- it is just a common marking shaped like a blotch on the horse's forehead. Unless you mean the whorl- that is the swirl of hairs where they meet on a horse, usually in the middle of the forehead or on the bottom of the neck. Each whorl is different, so it is like the equine fingerprint.
A sock on a horse's leg refers to a white marking that extends from the hoof to just below the fetlock joint. It is a common marking found on various horse breeds and does not have a specific meaning other than being a coat pattern.
Brown
That would definitely be the American Quarter Horse.