I got this off "Wikipedia".
Louisiana Créole refers to Americans of various racial descent who are descended from the settlers of Colonial French/Spanish Louisiana. The commonly accepted definition today is for the community whose members are a mixture of mainly French, Spanish, African American, and Native-American heritage. Some may not have each ethnic heritage, and some may have additional ancestries. Contrary to popular belief, a Créole does not exclusively pertain to persons of French and African descent.
Historically, Créole was used in early generations to refer to colonists of French descent who had been born in Louisiana and were thus native to the territory, compared to new immigrants. The word was also used for black slaves born in Louisiana, as opposed to those born in West Africa and transported from there. French Créole became the term for those of exclusively French descent after there grew a Créole population of mixed-race ancestry. Today, many multiracial Créoles of partial French descent also call themselves French Créole.
People of relatively pure African-American, French or Spanish descent with family roots in Louisiana who were raised under the Creole culture also have called themselves Creole. Today Louisiana Creole has come to mean those people of mixed ancestry. In the colonial and antebellum years, Creoles of color had formed a third class between Europeans and enslaved Africans.
Cajuns were always excluded from this distinction. They lacked social status in old Louisiana and were of mostly white Acadian background, although some were mixed race like Creoles. Due to this, some Cajuns might choose to refer to themselves also as Creole.