Item Status: An item can be Active or Inactive.
Inventory Status: An item can be In Stock or Out of Stock.
An Active item will be displayed in your online store.
An Inactive item will not be displayed in your online store.
You might want to set an item to Inactive status if you know it is not going to be available for purchase for a period of time. This will retain all of the item information in the database so that you don’t have to re-enter it later, but will prevent the item from being displayed in the store.
An In Stock item will be displayed in your online store, and will be available for purchase by shoppers.
An Out of Stock item will be displayed in your online store, but the Add To Cart button will be replaced by an “Out of Stock” indicator, and shoppers will not be able to purchase the item.
You might set an item to Out of Stock rather than Inactive if it frequently goes in and out of stock and you want your shoppers to be aware that you sell the item, but that it is temporarily unavailable.