Creole food, like Cajun food, is at it's root, French. The
French settlers who came to southern Louisiana mixed with the
locals, including Spanish, American Indians, and Blacks. They
incorporated a lot of the local ingredients into their dishes, but
retained the basics. A Creole gumbo, for instance, is more tomato
and seafood based, while a Cajun gumbo is more chicken and sausage.
They both start with a roux (oil & flour) onions, peppers, and
celery, but then move in somewhat different directions.