Primates are members of the order Primata, the order of placental mammals that includes human beings.
Aye-ayes, lemurs, lorises, tarsiers, monkeys and apes are primates. (A human being is a kind of ape.)
Primates have large brains in comparison to their body size.
A primate has a large, differentiated cerebral cortex - the part of the brain that is involved with consciousness and higher levels of thought.
The first primates, who lived between 65 and 85 million years ago, lived in trees.
Today, not all living primates live in trees; however, they all have physical characteristics that make them suited to an arboreal lifestyle.
Primates have large collarbones that link their arms to their chests. This arrangement allows them to move their shoulders in all directions, so they can grasp branches.
Their forearms and lower legs have two separate bones. This provides greater flexibility.
They have prehensile hands (hands that can grasp things) with flexible thumbs. All primates except humans also have prehensile feet.
There are sensitive pads at the ends of primates' fingers and toes. Instead of claws, primates have short fingernails and toenails.
Primates have an acute sense of vision. They can see in three dimensions, using stereoscopic vision (also known as binocular vision), and they can see colors.