is there much differences between behavior objects and class objects,

Hi, I am new learner on TGB, what i am thinking about is whether the behavior is useful or not and what are the differences between behavior objects(defined in folder of behaviors) and class objects(defined in folder of gameScripts). from my best knowledge of TGB, what the the behavior can do is also can be done by class,vice versus. but one thing is that somehow if we use behavior, then the code for the game program will be less and neat. beside this advantadge, what else can be figured out as its advantadges ??, I just have one month experience on TGB, so somehow if some words above is totally wrong, pls excuse me...