What is Promissory notes settlement?

After a Promissory Note issuance, a Borrower has two options to settle it and unlock his collateral. The first option, available at any time before the maturity date, is to bring back the same Promissory Note of the same amount. The second option is to wait for maturity date when the principal amount of promissory note will be automatically deducted from a Borrower balance.