A particular characteristic of many vultures is a bald head, devoid of feathers. This is likely because a feathered head would become spattered with blood and other fluids, and thus be difficult to keep clean.
Vultures fall into two groups. The Old World vultures belong to the family Accipitridae, which also includes eagles, Kitess, buzzards and hawks. These are found in Africa, Asia and Europe. They find carcasses exclusively by sight.
New World vultures and Condors are not at all closely related to the superficially similar Accipitridae, but belong in the family Cathartidae. They have a good sense of smell, unusual for a raptor.
The similarities between the two groups are due to convergent evolution rather than a close relationship.