Use for all listed products (Globally), only for products listed by store owners (Store owners), or only for products listed in stores (Store Listings). The Reserve Stock feature blocks from purchase, for a preset time, products from the shopping cart.
Sellers can set different prices for the same listing based on available stock, color, size, etc. It's also the best way to keep track of inventory and create special offers for soon-to-be out of stock products.
A sale isn't considered complete until the product is marked as Paid. Helps with keeping track of stock levels. Sellers can also enforce a time limit for payments. When not paid within the preset time limit, the sale is cancelled and the product is automatically relisted.