Grenades are explosive articles designed to be thrown by hand or by grenade launchers. The shape of grenades looks like pomegranate thus the origin of name grenade.
Most of the grenades are activated by a time delay fuse. To ignite the fuse user need to pull out a safety pin.
There are chemical grenades, gas grenades, incendiary grenades etc. Fragmentation and concussion grenades are anti-personnel coming under explosive grenade category.
Song dynasty of China (CE 960-1127) is known to be the inventors of first grenade. Below a quote from Huolongjing, written in 14th centuary
The shells (pào) are made of cast iron, as large as a bowl and shaped like a ball. Inside they contain half a pound of ‘divine fire’ (shén huǒ, gunpowder). They are sent flying towards the enemy camp from an eruptor (mu pào); and when they get there a sound like a thunder-clap is heard, and flashes of light appear. If ten of these shells are fired successfully into the enemy camp, the whole place will be set ablaze…
Grenades listed by Name in IMDG Code