A smoke grenade is a device that produces a dense cloud of smoke when ignited. It is commonly used in military operations, training exercises, and by law enforcement for various purposes, including signaling, concealment, and crowd control. The smoke can obscure visibility, making it difficult for opponents to see movements or positions. Smoke grenades come in various colors, which can indicate different meanings or uses. For example, green smoke might signal a safe area, while red smoke could indicate danger. They are typically cylindrical in shape and can be thrown by hand or deployed from a launcher.