Gallstones and removal of GB?

i found out i have gallstones and one of them is pretty big, so they want to take my gall bladder out, but what i want to know is...whats the point? the stones are keeping my gall bladder from doing its job right? and if the gall bladder is removed then its not there and not doing its job. so whats the benefit of taking out? someone please explain this all to me. and use stupid people terms please! : P