Common chimpanzees and bonobos are the two species of chimpanzees, our closest relatives.
Usually common chimpanzees are just called chimpanzees. Chimpanzees are very closely related to humans, human and chimpanzee DNA is about 99% the same. Several authors have pointed out that even the chimpanzee’s scientific name was chosen based more on our own vanity, or simply ignorance, and not based on the rules how taxonomists normally name a species. By those rules chimpanzees would not have the name Pan but should be called Homo, i.e. the species name of the common chimpanzee would rightfully be Homo troglodytes. If it was between any other two species there would not even be an argument about it, but we like to distinguish ourselves from the other lesser animals so we insist that others cannot share our name. Well, taxonomy was never among my favorite subjects anyway, such nonsense probably does not make me like it any better.
The average chimpanzee is less heavy than the average human but a lot stronger.
Being our close relatives chimpanzees can be savages and wage wars against their own kind.
Contrary to the popular belief that “monkeys eat bananas”, common chimpanzees have an omnivorous diet and they eat a lot of things including insects and smaller monkeys that they hunt down and tear to pieces.
Chimpanzees live in large groups that sometimes consists of over a hundred individuals. Males and females are both promiscuous. Males cannot ever be absolutely certain which offspring is theirs so they have to protect the entire group. This is rather different from the mating habits of other great apes especially gorillas where one male has a harem while others have nothing. Bonobos are even more promiscuous than common chimpanzees.
Chimpanzees are endangered in the wild because of habitat destruction, hunting for bushmeat and for the illegal pet trade.
You probably should not get a chimpanzee as a pet. Even if they are cute when they are babies they get nasty when they grow up and they tend to bite. Also in order to keep your pet chimpanzees happy you would have to keep a large number of individuals together so that they can form a proper troop of their own kind. The required space and other resources can be significant. Chimpanzees are also susceptible to human diseases so your pet chimpanzee probably would catch everything you do and you could get something nasty from him or her. It might also very well be illegal in your jurisdiction to keep a chimpanzee as a pet.
Further Readings:
Common chimpanzee on Wikipedia.
Western chimpanzee on Wikipedia.
Chimpanzee on Wikipedia.