Difference between Bill To, Ship To & Deliver To in Oracle Apps

Sold To  is nothing but to whom you actually selling to.

Bill To is who gets the invoice.  The list of choices here is dependent on the profile option "OE: Customer Relationships"

•      If the profile is set to No, then the Bill To can only be a bill to location of the Sold To customer.
•      If the profile option is set to Yes, then the Bill To can be a bill to of the Sold To customer or any customer with a defined relationship to it.
•      If the profile option is set to ALL, then the Bill To can be any bill to location of any customer, even if they're not related to the Sold To.

Ship To is the location that generally gets the material.   It's also dependent on the profile option "OE: Customer Relationships"

•      If the profile is set to No, then the Ship To can only be a ship to location of the Sold To customer
•      If the profile option is set to Yes, then the Ship To can be a ship to of the Sold To customer or any customer with a defined relationship to it
•      If the profile option is set to ALL, then the Ship To can be any ship to location of any customer, even if they're not related to the Sold To

Deliver To isn't dependent on anything.  You can select any location from any customer.