The inventory is where the player can store all of the items and tools that they would like to have with them while exploring.
Inventory size is fixed to 40 slots in a 4 by 10 arrangement in the inventory screen, not counting the hot bar which is 10 slots making total inventory size to be 50 slots.
Items in a certain category such as potions, ammo and food can be stored in a single slot with the use of the potion pouch, ammo pouch or lunchbox providing 10 slots of inventory only for the respective item categories.
The Void Pouch provides 20 additional inventory slots but cannot be stacked (each additional pouch of this type will share the same inventory menu).
The Void Bag is similar but provides 40 additional inventory slots