Stack

A stack is full amount of items that a player can hold in one inventory slot. A stack usually refers to two or of the same items in the same slot, so a sword is not 'stackable'. Because most items can be stacked at a maximum of 64, a group of 64 items is refered to as a 'full stack', with 32 items being a 'half stack' and so on.

I wish a saddle could stack