Both are mayonnaise-based sauces with some common ingredients (depending on the recipe). However, to me, that's where the similarities end. My basic purpose for a tartar sauce is as a condiment for fish and seafood, either fried, broiled, baked, or grilled. Tartar sauce usually has sweet or dill pickle relish teamed with the tartness of lemon, vinegar, and fresh dill. I sometimes use capers. Check out my Creole Tartar Sauce recipe right here. Personally, I think this White Remoulade Sauce is much more versatile than tartar sauce.