Banana peppers and pepperoncini peppers differ in three ways: appearance, heat, and flavor. The banana pepper has smoother, thicker skin that looks like a banana’s, while the pepperoncini’s skin is wrinkly and has bends and pock marks. The heat on the two is often similar, except that the banana pepper can dip to a zero heat while the pepperoncini can't. The biggest difference is the taste. Both types are mild and a little sweet, but banana peppers are tangy and pepperoncinis are slightly bitter.