Apes refers to all members of the superfamily Hominoidea, which humans belong to. Much as mammals refers to all members of the class Mammalia. There are large amounts of fossil evidence to corraborate a close link between modern humans, their ancestors, and their brothers likes chimps and orangutans.
For example:
This
vs this
Also, bonobos are the closest living relatives of humans, not pigs. Even higher DNA similarities than chimps.