What is the Difference between Bass amp and Guitar Amps?

Answer 1

Quality. The oldest or least expensive amps usually goes to the bass and the best goes to the Guitar amps.
The whole sound systems is undergoing many changes and here is a link to one of these sound systems.

Answer 2

Bass amps use bigger, heavier speakers to handle the low frequencies. Usually the speakers are 15 inches. Guitar speakers are often 12 inch and can't handle bass frequencies played at loud volumes. You can play a guitar through a bass amp without a problem but you should not play a bass through a guitar amp or you are risking blown speakers.