A quick overview of Each Stock Status element in Magento
In the concept of unlimited stock, a store is selling an item that is stocked all the time or easily restocked if on-hand supplies get low. Alternatively, this method could be used for drop shipping as well.
Out of Stock
For items that are seasonal, limited run, custom, or otherwise hard to maintain a consistent inventory, the Out Of Stock method allows you to display information about the product but removes the ability for the shopper to purchase. There is an advanced feature that allows you to do “in-stock notifications”
Commonly, when an item is sold out, it is ideal to allow the customer to still add the item to their cart and to checkout. This creates a back order.
Quantity on Hand
There are certain projects that require a shopper to pick an available product based on the quantity available. In this case, it is important to maintain real-time inventory status.
Extending upon the real-time inventory status, the geographical location of the available items could affect the shoppers behavior. This could lead them to purchase other items that are closer to their location. At the least, it will create an expectation of delivery times.
This is a way to expand your online catalog without having to increase your inventory. There are many ways spin this: