It is the actual yearly interest rate paid by the borrower, including the points charged to initiate the loan and other costs. (rismedia.com)
The twice - yearly interest payments also would increase, because they would be based on the new, higher principal amount. (fidelity.com)
I often see banks advertise (for accounts with fixed yearly interest, let's say 1.5 %)-- «interested is calculated daily, and compounded monthly». (money.stackexchange.com)