Coated cast iron pans are glazed with an enamel coating. This eliminates the need for seasoning and makes it easier to clean them. It also prevents iron from leaching into food. Enameled cast iron, however, doesn't resist sticking as well as seasoned bare cast iron. It also doesn't withstand searing heat and can chip easily if dropped.
Fry pans are specifically designed for frying and can be used to fry almost anything with less oil than deep-frying. They can also be used for other cooking methods and are versatile enough to replace other pots.