This poor man's grenade was lit and thrown at armored cars and the like. In 1956, the outgunned freedom fighters in Hungary used the Molotov Cocktail against the Russian oppressors. By the time of the Korean war, the grenade was lighter, and fragmented more easily, and by the time of Vietnam, American GIs had light, reliable grenades that exploded five seconds after the pin was pulled, killing up to 15 meters, and injuring up to 35. They had a thin shell, and dispensed thousands of tiny, jagged steel strips. Many a GI must have been grateful for early Baseball training.
Fragmentation grenades are the most common, but there are other types.
Also used in war were illuminating grenades, for lighting up enemy positions and parachute drop zones, and incendiary grenades, to spread fire. Used by both the army and civilian police forces are the chemical or gas-grenade, and the smoke grenade. As the balance between defensive and offensive warfare changes, so does the role and efficacy of the grenade. Grenades will certainly used in future wars. According to the Starfleet Manual, it has twenty settings, which vary its effects from stunning through killing, through total destruction.