There are only six apes on Earth: gibbons, orangutans, gorillas, chimpanzees, bonobos and humans. As you can see, all ape skeletons are extremely similar and have most of the same physical components.
All apes are classified in the Hominoidea superfamily but are divided into four families. Gibbons are in the lesser ape family, though they can walk upright and have similar skeletal proportions to humans. Orangutans and gorillas each have their own subfamilies, but chimpanzees, bonobos and humans are all in the homininae subfamily.
The tree above shows you the order in which apes evolved and the closer the branch on the tree, the more closely related the apes are. The most recent apes and closest relatives of humans are chimpanzees and bonobos, but gibbons are our most distant ape cousins.