Goodnight's right. Fact and theory.
Evolution as a process: FACT
Evolution of ape to man: THEORY
Evolution is a demonstratable phenomenon that is constantly occuring. With every passing generation of every species, that species will evolve somewhat to adapt to its conditions. In people, the most common occurence is with skin colour. Do you think that it's a fluke that people living in northern, colder regions have light skin, and people living in southern, warmer regions have darker skin? It's not. They're all human, but after thousands/millions of years, the skin colour changed in order to accomodate the conditions. If it's warmer, that usually means that the sun is stronger in that area, so the skin darkens in order to be able to resist being burned. That's by a black guy will rarely get very serious sunburn, but my red-headed, white mom can barely go outside without SPF 45 and a hat without turning red. People from mediterranian are somehwere in between and are sort of light, sort of dark, and get tan in the sunlight. Evolution is basically slow adaptation on a genetic level.
As for evolution of ape to man, that is just a theory. albeit a very supported and likely theory, a theory nonetheless. There have been countless of archeological finds that have proven that early man was in fact somewhat ape-lke and did eventually evolve into what we look like today, but there is no actual proof that we did start as apes. The theory says that some apes in Africa decended from the forested areas (for some reason) into the flat, open plains. Thehy would climb what few trees there were, but once the food ran out they would have to get out and move again. Their inability to run quickly would make them easy prey. Eventually, the apes would learn to try and look over the tall grass, since their hind legs were strong enough to stand for small amounts of time, to see if a predator was coming. They could then run away accordingly. Theoretically, after spending so much time peering over grass on their hind legs, they gained the ability to stand for longer and longer. This would go on until they were always upright. This is why early man appears hunched over. What's missing from this is the crucial "missing link", as it's called, which bridges the transformation from ape to man. Because of what we do know, that theory is very, very likely. Only, it can't be proved since the crucial piece is missing.