i think the important difference to understand, is that even creationists believe in a form of evolution. There are fossil records to prove it, and only the most stubborn refuse to see it. but that is an evolution within one species. horses evolving into somewhat different horses, etc. what most creationists do not believe however is evolution from one species to another. apes to humans for example.

the crucial piece of evidence for me is; in all the fossils and remains that have been uncovered, there has never been found any fossils or evidence of a link or missing link. not one fossil of a creature evolving from one species to another. with the thousands or millions of years it would take to evolve, it seems that there would be many so called links.