Blanket. Create blanket purchase agreements when you know the detail of the goods or services you plan to buy from a specific supplier in a period, but you do not yet know the detail of your delivery schedules. You can use blanket purchase agreements to specify negotiated prices for your items before actually purchasing them. Blanket purchase agreements can be created for a single organization or can be shared by different business units of your organization (global agreements). You can encumber funds for a blanket purchase agreement.
Contract. Create contract purchase agreements with your suppliers to agree on specific terms and conditions without indicating the goods and services that you will be purchasing. You can later issue standard purchase orders referencing your contracts, and you can encumber these purchase orders if you use encumbrance accounting.