You described the Cajun Creole thing almost perfectly. There is geographic component that comes into play as well. Creole tends to involve New Orleans and Cajun things west of New Orleans and generally south of Alexandria. The Creole influence involves primarily two things... New Orleans was populated by white french peaking people and black people who hailed (generally) from Africa by way of Haiti and Martinique. The food tends to be 'slow food", soups, stews, etc. that are cooked in pots and have ingredients added along the way. There is an antique cookbook that is the premier example of this type of cooking. "Madame Begues Cookbook" which is still available from online sources is not only a great history book, but also aa really interesting historical document. Many of the recipes prove that the 18th and 19th century fine food diner wa s able to enjoy a wide (if not wider) variety of food than just the usual pork and seafood products we see today. There are lots of freshwater fish recipes in this book and tons of game (that is now protected from commercial use) that can no longer be served in restaurants.
The cajun thing has more to do with what poor immigrants ate after they got kicked out of Canada. Native foods (both veg and seafood) amde up the majority of the cajun diet, along with grain staples (primarily rice) which were served with virtually everymeal. Rice goes along with everything, and into anything (even sausage, boudin, yummmm).
Then, to make everything really complicated, we throw in the Medditerranean (mainly italian sicilian) influence on New Orleans in the late 19th century. Creole/italian is a real and vital part of food in Louisiana. There was a huge population of immigrants from those areas (the classic ninth ward N.O. accent is exactly like a classic Brooklyn accent), and their food blended in nicely with the creole "pot" dishes. Moscas, in beautiful Boutte, LA., is the prime exmple of this type of cooking, although there are a hundred others. While tourists and other foriegners
think of Boudin and Andouille and the Louisiana sausage, most grocery store stock as much or more italian (freshmade) sausage than they do the other types. When you come down for your wedding I will give you a list and you can eat your way to a decision about the differences.