The beef is corn fed. Corn fed beef. Corned beef. Like so many things here, we just remove a word. - This is not true. it has to do with the preserving or cooking process. Corned Beef is a brisket that has been Brine. Process takes about 7 days in the solution then is cooked.
Corned beef and cabbage is a popular dish, especially at Saint Patrick's Day. The name can lead to confusion and cause one to assume that there is corn in corned beef. However, there is no corn in corned beef.
Corned beef is derived from cattle (beef), not from pigs (pork). Also, don't mistake 'corned beef' for 'corn-fed beef'. 'Corned beef' is a brine cured cut of beef, whereas 'corn-fed beef' is cattle that were fed corn as opposed to other grains.