Delivery Return
Delivery Return: brings back goods against the delivery challan they left on, or sends back goods against the receipt they came on, in the same batch and at the same price.
Sales Return
Sales Return: receives goods back from a customer against a sales return order, and can raise the customer credit memo.
Purchase Return
Purchase Return: sends goods back to a vendor against a purchase return order, at the cost they were received at, and raises the vendor debit memo.