As of 2014, there are more than 260 different species of monkeys in the world. Monkeys are often divided into old world monkeys and new world monkeys, depending on where they live in the world. Monkeys should be distinguished from apes, as most monkeys have tails and apes do not.
There is information to suggest that monkeys have been around for roughly 50 million years, evolving from early primates. Various species of monkeys range in size from four ounces to roughly 77 pounds. They live in a variety of environments and eat a variety of foods, although most eat fruit and insects.