What is the difference between modern jazz dance and jazz?

This might sound stupid but whenever I see dance classes listed on dance studio sites, they have 2 classes named jazz dance and modern jazz dance. Aren't they the same (well, according to wiki)? I'm starting to second guess myself.|||It is not a stupid question. I would wonder what they meant by that too. Small dance studios tend to make up names for things and they mean different things in different studios. Technically you are correct when it comes to professional dance. However, you never know what a small studio is calling one thing or another. My advise is to check out a class and see what they mean. It could be street jazz or more likely a lyrical/contemporary competition dance style. Who knows.|||Jazz dance is just the regular jazz that every dancer know about...modern jazz dance incoporates elements of lyrical and ballet techniques.