Grenades are explosive devices used in warfare and law enforcement. They typically consist of a metal or plastic casing filled with explosives, fragments, or chemicals designed to have a specific effect. Examples of grenade types include fragmentation, smoke, stun, incendiary, and gas. They can be thrown or launched from a grenade launcher, and are often used to clear out enemy positions, provide cover or concealment, or incapacitate targets. Grenades are highly effective weapons but also pose a significant risk to civilians and non-combatants if not used properly.