If you use only one location to store your inventoried items

If you store your inventoried items in one location, you won't use the multiple locations feature.

Because you have only one location for all of your items, all of your items will be sold from and shipped to one location automatically. You won't have to indicate a location on sales and purchases. In fact, the column used to select a location -- the Location column -- won't appear in the Sales and Purchases windows. (As soon as you add a second location, though, the Location column will appear.)