Purchase Order: The document which is created and sent to supplier when we need to purchase something. (Buying) Sales Order: The document which is created when customer places an order to buy something. (Selling)
A validation template names a condition and defines the semantics of how to validate that condition. Validation templates can be used in the processing constraints framework to specify the constraining conditions for a given constraint.
A method of fulfilling sales orders by selling products without handling, stocking,or delivering them. The selling company buys a product from a supplier and has the supplier ship the product directly to customers.