What It Means
Accrued interest is the interest amount that is earned/accrued since the last payment was made. If you pay accrued interest then the outstanding amount is the unpaid principal amount. Accrued interest becomes interest payable on the due date. For example, assume you make payment on the first of each month for the previous month's interest. On 15 January accrued interest would be the amount of interest from the 1st Jan to 15th Jan. This amount is not due on 15h Jan, instead the entire January's interest will be due on Feb 1.