There under 4 categories of items(Weapons, Armors, Vehicles and Special) that are used by player and mob members when attacking or defending against other players. More powerful items become available as you increase in level. Some of the Armory is only for one time use, which means these get used up in a fight. These items will also be consumed in missions which require such items for completion. Some items called Loot items cannot be bought and can only be gained by doing missions. Muti-buy is single item can be done by clicking on the image of the item in the Armory.