Are Crappie, Brim, and Sunfish the same type of fish? I have always thought they were basically the same type of fish. A friend told me they were different fish.

They are all similar fish but they are certainly different species, each with its own differences that make a change in the approach an anglers take while fishing for them. There are many different kinds of Sunfish. In fact if you wish to be technical all of the fish you mentioned along with Largemouth Bass, Smallmouth Bass and several others are part of the Sunfish family. Brim, also referred to as Bluegill, are the most common member of this family. They are very close cousin to most of the different kinds of Sunfish. Some other forms of Sunfish include the Green Sunfish, Redear Sunfish (also called Shell crackers) and Pumpkinseed. All of these fish are very similar in selected habitat and other characteristics but are indeed different species. The Crappie is the one fish you mentioned that is quite different than the others. A Crappie has as much if not more in common with a Largemouth Bass than it does a Sunfish or Brim. The only real link with these fish is the size of their body. Their behavior and selected habitats are more in common with Largemouth Bass. As an angler you should take the time to identify each of the various species of pan fish. It can be important when you consider different laws in effect. You would not want to break a law concerning fish limits or minimum size required to keep a particular fish. As sportsmen it is our responsibility to know each of the species and act in accordance with the law.