Berry

Berry (item)
A berry is a sub-category of an Item that was first introduced in Pokemon Gold and Silver Versions during the 2nd Generation. There are several dozen shapes and forms of berries, each with their own unique effect which can vary from healing 10 HP as an Oran Berry, to healing all Status Conditions as an Oran Berry.

Use
Berries can be held by all Pokemon and when held will be used in battle at a random but usually necessary and convenient time. However, once a berry has been used, it will be discarded and the Pokemon holding it will no longer be holding an item.