Durability is an item statistic seen on armor and weapons that depletes the ability to use an item. If the durability reaches 0 on an item, the item will break, though if it reaches 0 durability during warfare the item will break after the war has ended.
Ways to increase Durability
The durability of an item/armor can be increased using enchantments. The enchantments that increase durability are Unbreaking I, Unbreaking II, and Unbreaking III.
Note: Not all items can have their durability increased.