Private property is a concept used in law. Law says that a single person, or a group of people can own certain things, and control them. All the things that are not owned by single persons, or a group of people belong to all. That way, a person may own a car, but the park in the city is only administered by the city, and belongs to all people (or to no one at all). Different schools of thought have different ideas of how private property should be handled. According to Capitalism, private property is needed so that a society can work as it should. That way, trade can only be done using private property. Socialism and Communism believe that certain things can not be owned by an individual or a group of people, as they are used to produce other products or provide services.