What is the difference between TO and PO ?
In Simple Terms
TO : Transfer Order : Used when Store A does not have product and Store B have same product. In this case transfer order can be created to move the product from Store B to Store A.
PO : Purchase Order : Used when Store A does not have product and only available with vendor. So purchase order can be placed to buy the product from vendor and make it ready/available for customer.
TO(Transfer Order) - Transfer items DC to DC or DC to Store or Store to Store with in same Organization
PO (Purchase Order) - Physically Stock not available with in organization, but we will full fill from outside organization.