Is the same cut of beef used to make beef brisket and also for corned beef?

Traditionally they are both from the same cut...beef brisket has a lean side and a fatty one (more flavorful but will clog arteries. It was the cut that was corned (preserved w. spices.) Both delicious. Today, unfortunately, delis will serve (and markets will sell) corned beef made from other cuts - chuck or rump, I think, that are gristly and yucky. The traditional butcher or Jewish deli is your best bet for old-fashioned corned beef.

Oops. Other cut of corned beef is the beef round; not so tasty and not worth bothering with.

also, why is it corned beef when there is no corn involved? I think I read something once that "corn" used to mean grain, and so you used to be able to say "corns of salt" and that's why you say corned beef (salted beef). I can't remember where I read this though. Does anyone know if it's true?

From Wikipedia: Corned beef is a cut of beef (usually brisket, but sometimes round) cured or pickled in a seasoned brine. The "corn" in "corned beef" refers to the "corn" or grains of coarse salts used to cure it. The Oxford English Dictionary dates the usage of "corn," meaning "small hard particle, a grain, as of sand or salt," to 888, and the term "corned beef" to 1621.