Inventory slots represent the ability of a creature to equip items, making those items worn or wielded as appropriate. Each slot can hold only one item at a time, and items can be placed in only certain slots, depending on the type of item. Items in a slot are considered "equipped" and able to be used. Items that can go into a slot but are not currently in one cannot be used.
A player character's inventory slots are displayed in the top part of the inventory panel (unless a container is opened, in which case that part of the panel is used for the container's inventory). Players can equip items by dragging them from the main inventory (considered the character's backpack) to the slot, and unequip them by dragging in the reverse direction. Possessed items can also be equipped and unequipped via the radial menu—"equip" is the rightmost option, while "unequip" is leftmost. As a special case, items that can go in the off-hand slot have "equip off-hand" as their leftmost option (and no rightmost option unless they can go in another slot as well). This allows a player to dual-wield via the radial menu. The radial menu should not be used when interacting with a store, though, as the "equip" option is replaced by "sell" in that circumstance.