Hello,
In WooCommerce, if you do not check “Track stock quantity for this product”, the product inventory will not be displayed on the frontend, and customers will always be able to purchase the product regardless of the available quantity. This means that the product will not be out of stock no matter how many quantities are purchased.
On the other hand, if you check “Track stock quantity for this product” and enable “Allow backorders” with the option “Allow, but notify customer”, the customer will be notified on the product page that the product is out of stock and can still place an order, but it will be marked as a backorder. The notification message will depend on the theme and settings you are using.
Best Regards.
.
