What I've heard creole defined as (NicholasW or Akatsukami would be better) is the step after pidgin.

Pidgins develop when two cultures meet for the first time and cobb together a language with words jumbled together from each language and a very rudimentary grammar. Creoles are the languages put together by the people who grew up with the pidgin. Apparently they have a grammar all their own that is comparable to the grammar of other creoles. This is something that has interested me but that I have not had the chance to dig into very deeply.