Because all electrons, nucleons, and other particles undergo a persistent spin motion without having any source of infinite energy, they should have a unique structure that keeps them persistently spinning and provides all the properties that they display. In addition, there should be some reason or purpose why they show a persistent spin motion, because, in nature, nothing occurs without a reason or purpose. Research on the present topic attempts to determine the unique structure of neutron, how neutron possesses a persistent spin motion through its unique structure, and the purpose why it has such persistent spin motion. These determinations provide very clear and complete explanation of all the properties of neutrons, including two very important properties about which the people were not known before, as well as all properties and structures of their (neutrons) systems, e.g., deuterons, alpha particles, and nuclei, generated due to them.