Apes are the members of the hominoidea superfamily of primates, which includes humans. Under the current classification system there are two families of hominoids:
The family hylobatidae consists of 4 genera and 13 species of gibbons, including the Lar Gibbon and the Siamang, collectively known as the "lesser apes"
The family hominidae consisting of orangutans, gorillas, chimpanzees, and humans, collectively known as the "great apes".
Within the superfamily Hominoidea, gibbons are the outgroup: this means that the rest of the hominoids are more closely related to each other than any of them are to gibbons. Investigation showed orangutans to be the outgroup, but comparing humans to all three other hominid genera showed that African apes (chimpanzees and gorillas) and humans are more closely related to each other than any of them are to orangutans. How ever, DNA comparisons from sex chromosomes and autosomes provide convincing evidence that within the subfamily homininae, gorillas are the outgroup. This suggests that chimpanzees should be in hominini along with humans.