The most important feature of a shotgun is the shell: a plastic hull that contains small pellets (shot) or a lead ball (slug), wadding, and powder.
Depending what’s in the shell you can aim to kill or wound, be exact or broad, hit a distant target or plan for close-up. A shotgun is useful in various scenarios where the different firing options are ideal. A shotgun can fire flechettes, birdshot, rock salt, rubber pellets, bean bags, sabots, buckshot or slugs. This is not even a complete list but just an indication of the wide-ranging shot options for a shotgun. For use in home defense, shells that contain slugs and buckshot will be discussed in more detail in the section on ammunition.