Canister shot was a type of ammunition used in early warfare, consisting of small metal balls or pellets packed into a metal canister or case. Synonyms for canister shot include grape shot, shrapnel, and case shot. Grape shot was similar to canister shot but consisted of small iron balls instead of pellets. Shrapnel referred to the actual metal casing used to hold the shot, which would explode in mid-air and scatter the shot over a wide area. Case shot referred to the metal canister used to hold the shot, which would burst upon firing, releasing the pellets inside. All these types of ammunition were used in the same way, by firing them from a cannon or other artillery piece at close range.