Which is the payment term which actually gets defaulted in transaction (accounting view or purchasing view)?

The payment term in the accounting view of the vendor master comes
into picture if the transaction originates from the FI module. If an FI
invoice is posted (FB60) to the Vendor, then the payment terms is
defaulted from the accounting view of the vendor master.

The payment term in the purchasing view of the vendor master comes
into picture if the transaction originates from the MM module. A
purchase order is created in the MM module. The payment terms are
defaulted in the purchase order from the purchasing view of the vendor
master.