The 21-gun salute is often confused with the symbolic act of firing three volleys at military funerals, but these are two completely different rituals. The "21-gun salute" is, as the name states, a salute (i.e., an expression of welcome, goodwill, or respect), and in that context the word "gun" refers to naval guns or artillery pieces (typically cannon), not firearms. The firing of three (rifle) volleys at military funerals is technically not a salute but rather a funereal custom, perhaps derived from a superstition of discharging firearms to frighten evil spirits away from the grave, or possibly a recreation of the act of firing three volleys to signal the end of a temporary truce (called to allow each side to clear their dead and wounded from the battlefield). Even when a military funeral detail includes seven members (each of whom fires his rifle a total of three times), this ritualistic act is something distinctly different and separate from the custom of saluting dignitaries by firing 21 guns in their honor.
