The Purchases window allows you to create transaction records for the items and services you buy. The window has four views. Depending upon the type of transaction you're entering in this window (item purchase, service purchase, professional purchase or miscellaneous purchase), the fields will change to allow you to enter appropriate information. Each of these views, with their different sets of fields, is determing by the layout.
Use the Purchases window- Item layout, if you want to create a purchase that's used to record the purchase of items and services for which you selected I Buy This Item in the Item Information window. When you record an item purchase, your in-house quantities of the items for which you also selected I Inventory This Item in the Item Information window (also known as inventoried items) listed on the purchase change accordingly.
To find the Purchases window - Item layout