A common name, rather imprecise, for some animals of the order Primates. At one stage it often meant the family Pongidae (Gorilla, Chimpanzee and Orangutan), but that family seems to have been banished by the cladists for being paraphyletic.
There is also a usage (and this may well be the original one in English) where "ape" refers to the baboon, from yet another branch of the primates.
All these ideas point at wild animals, somewhat resembing humans, but covered in hair and often preferring to walk on all fours. Most kinds of apes climb trees. They do not have tails, except for the baboon. Their diet is best described as omnivourous, consisting of fruit, grass seeds, and in most cases small quantities of meat (either hunted or scavenged), along with anything else available and easily digested.
Since the concept includes some quite different animals, most of the information should be on the individual pages. But perhaps some common information could go here. Perhaps something about conservation issues? (Most ape species are rare or endangered.)