Apes are Old World anthropoid mammals, more specifically a clade of tailless catarrhine primates, belonging to the biological superfamily Hominoidea. The apes are native to Africa and South-east Asia. Apes are the largest primates and the orangutan, an ape, is the largest living arboreal animal. Hominoids are traditionally forest dwellers, although chimpanzees may range into savanna, and the extinct australopithecines are famous for being savanna inhabitants, inferred from their morphology. Humans inhabit almost every terrestrial habitat.

Hominoidea contains two families of living (extant) species:

Members of the superfamily are called hominoids (not to be confused with "hominids" or "hominins").

Some or all hominoids are also called "apes". However, the term "ape" is used in several different senses. It has been used as a synonym for "monkey" or for any tailless primate with a humanlike appearance. Thus the Barbary macaque, a kind of monkey, is popularly called the "Barbary ape" to indicate its lack of a tail. Biologists have used the term "ape" to mean a member of the superfamily Hominoidea other than humans, or more recently to mean all members of the superfamily Hominoidea, so that "ape" becomes another word for "hominoid". See also Primate: Historical and modern terminology.

A hill is a landform that extends above the surrounding terrain. Hills often have a distinct summit, although in areas with scarp/dip topography a hill may refer to a particular section of flat terrain without a massive summit (e.g. Box Hill, Surrey).

The distinction between a hill and a mountain is unclear and largely subjective, but a hill is generally somewhat lower and less steep than a mountain. In the United Kingdom geographers historically regarded mountains as hills greater than 1,000 feet (300 m) above sea level, which formed the basis of the plot of the 1995 film The Englishman Who Went Up a Hill But Came Down a Mountain. In contrast, hillwalkers have tended to regard mountains as peaks 2,000 feet (610 m) above sea level: the Oxford English Dictionary also suggests a limit of 2,000 feet (610 m). This has led to Cavanal Hill in Poteau, Oklahoma, receive billing as the "World's Tallest Hill" due to its height of 1,999 feet (609 m). Mountains in Scotland are frequently referred to as "hills" no matter what their height, as reflected in names such as the Cuillin Hills and the Torridon Hills. In Wales, the distinction is more a term of land use and appearance and has nothing to do with height.