What is the difference between clean and clean up?

Your clothes can be clean. Your car can be clean. An object can be clean. However, "to clean" is an action of taking something that is dirty or messed up to make it clean or tidy. We say "Go clean your room" as the shortened expression of "Go to clean your room". Then, toys, papers, clothing that are in disarray are cleaned up. Meaning put away or stored for later use. A person may "clean house", to do actions that serve "to clean" objects and areas, which we express as "clean up".