Lump or backfin - large, whole lumps of meat from the body of the crab. This is usually the most expensive meat and is often used in salads and special dishes.
Flake (regular) - all meat from the body portion of the crab except lump.
Claws - all meat form the claw appendages.
Crab claws - claws of the crab with the shell partially removed. These are most often used as appetizers.
Pasteurized crabmeat - canned lump crabmeat, which is found in the refrigerated section of the supermarket. It will keep for about 6 months, unopened, in the refrigerator. Once opened, the crabmeat will stay fresh 3 to 5 days in the refrigerator.
And then there are 'live crab' and here is how you handle cooking and cleaning them. The live crab are put into a pot of boiling water and cooked 8-10 minutes, depending on the size. The shells will turn a bright orange color when done. Drain in let cool enough to handle.
Leaving the legs on, break the claws from the crabs at the body. All meat in the claws is edible, dark but tasty. Crack claws with a hammer, nutcracker or better yet, a store-bought claw cracker. To clean the body of the crab, the secret is a sharp knife. Remove the shell by holding the crab firmly underneath and pull up on one of the points of the shell. You will then see the fat and gills. Scrape away the yellowish fat form the middle cavity. The fat is edible, but too oily for most. Scrape away the feathery gray gills. Cut off the walking legs well into the body. There is very little meat where the legs join the body. On large crabs, save the legs since there is good meat in them.
With the cavity up, slice through the sides horizontally. Lay knife blade flat in cavity and then cut off.. This is really easy to cut and leaves the body of the crab exposed for easy picking with the point of your knife or fingers.
This method of crab-picking came from an old cookbook that had been separated from its cover, not allowing me to even know its name, and really in pretty bad condition. But to me, it's condition has nothing to do with the wonderful recipes and tips that I found among its pages.