Hi 

The Ship-to Party refers to the party to whom the goods or products are to be shipped or delivered. It represents the customer or the recipient of the goods. The Ship-to Party is responsible for receiving the products at the specified delivery address.

On the other hand, the Bill-to Party refers to the party who is responsible for the payment of the products or services. It represents the customer who will be billed for the goods or services provided. The Bill-to Party is typically the party that receives the invoice and makes the payment.

In some cases, the Ship-to Party and Bill-to Party can be the same, especially when the customer is both the recipient of the goods and the payer of the invoice. However, there are also situations where the Ship-to Party and Bill-to Party can be different, such as when a customer wants to ship the products to a different location than the billing address.

To get some more information partner functions in SAP check the link: https://help.sap.com/docs/SAP_CUSTOMER_RELATIONSHIP_MANAGEMENT/cb77bf16eae9401fb7c569c5ac3b4bb6/463e6d80fddf2f91e10000000a1553f6.html