Forks are used for every stage of food consumption: from growing the food, to food preparation, to serving, and finally to eating.
Their use is ubiquitous now, and in the West, we take them for granted.
Not all cultures use them for all stages, however, and even in the West their use at the table is a relatively recent historical development.
Types of forks
A blending fork (aka mixing fork) is a fork with over-sized space between its tines and a thick, sturdy handle. It can be used to cut and blend fat into flour, mix dry or wet ingredients, for serving meat, for fluffing rice, etc.
Ice Cream Forks
Ice cream forks have a flattened bowl reminiscent of a spoon, but with tines cut into the tip of the spoon. They make it easier to eat frozen or semi-frozen desserts because they can dig easily into hard, frozen ice-cream.