Inventory is where things are when they are not wielded in your hands, stored in a container, or placed in your rift. Anyone with the ability to appraise will see the contents of your inventory unless security measures have been taken.
Theft of inventory items can be prevented through several ways. Inventory items may be concealed by an shimmering orb, while artefacts may be hidden from sight with an Orb of Suppression. Also, the selfishness ability will cause one to be too stingy to give away a single item.