Items in this game are grouped into the following categories:
Tools: consumable items, quest items, key items, etc.
Weapons: some weapons are only equippable to one character, but some can be shared among more than one
Armor: some armor can also be shared among more than one character (most notably, any "dress" armor can be equipped by any female)
Accessories: accessories can be equipped by anybody, and mostly offer stat boosts or resistance to magic or status ailments
Some items can only be synthesized, and some can only be obtained from monster drops or steals.