San people have been living in southern Africa since there first were human beings anywhere, maybe about 100,000 years ago. There are more than 14,000 of these paintings in South Africa. Nobody knows when San artists first started making rock art. They are still doing it today. But we do know about when the San people first got pushed into the Kalahari Desert. That was about 400 AD. So the San rock art from other places in south Africa must be from before 400 AD, and the San rock art from the Kalahari must be from after 400 AD.
A few of the paintings seem to show real things that happened, like small San people fighting the big Bantu who are invading them. More of them seem to show mythological stories about the past. Or they show dreams that San holy men had about the spirit world.
There were different styles of drawing in different parts of Africa, and different kinds of animals were painted in different places too.