An ape is any member of the Hominoidea superfamily of primates. In less scientific language, it has various meanings, although it often (but not always) excludes humans. Due to its ambiguous nature, the term 'ape' is less suitable as a means of describing taxonomic relationships.

Under the current classification system there are two families of hominoids:

• the family Hylobatidae consists of 4 genera and 14 species of gibbon, including the Lar Gibbon and the Siamang, collectively known as the lesser apes.
• the family Hominidae consisting of chimpanzees, gorillas, humans and orangutans collectively known as the great apes.

A few other primates, such as the Barbary Ape, have the word "ape" in their common names (usually to indicate lack of a tail), but they are not regarded as true apes.

Except for gorillas and humans, all true apes are agile climbers of trees. They are best described as omnivorous, their diet consisting of fruit, grass seeds, and in most cases some quantities of meat and invertebrates—either hunted or scavenged—along with anything else available and easily digested. They are native to Africa and Asia, although humans have spread to all parts of the world.

Most ape species are rare or endangered. The chief threat to most of the endangered species is loss of tropical rainforest habitat, though some populations are further imperiled by hunting for bushmeat.

Biology

The gibbon family, Hylobatidae, is composed of thirteen medium-sized species. Their major distinction is their long arms, which they use to brachiate through the trees. As an evolutionary adaptation to this arboreal lifestyle, their wrists are ball and socket joints. The largest of the gibbons, the Siamang, weighs up to 23 kg (50 lb). In comparison, the smallest great ape is the Common Chimpanzee at a modest 40 to 65 kg (88 to 143 lb)

The great ape family was previously referred to as Pongidae, and humans (and fossil hominids) were omitted from it, but there is no biological case for doing this. However, this definition is still used by many anthropologists and by lay people. However, that definition makes Pongidae paraphyletic, whereas most taxonomists nowadays encourage monophyletic groups. Chimpanzees, gorillas, humans and orangutans are all more closely related to one another than any of these four genera are to the gibbons. However, the term "hominid" is still used with the specific meaning of extinct animals more closely related to humans than the other great apes (for example, australopithecines), even though "hominin" is now correct in that usage. It is now usual to use even finer divisions, such as subfamilies and tribes to distinguish which hominoids are being discussed. Current evidence implies that humans share a common, extinct, ancestor with the chimpanzee line, from which we separated more recently than the gorilla line.