A federal law that requires a lender to give borrowers the annual percentage rate (APR)

The APR helps borrowers compare one loan to another since it factors in not only the interest rate but also all the fees and closing costs that you need to pay. APR, though, is not always the best measure of comparison since not all the lenders include the same fees and closing costs. Regulation Z is also called the Truth-in-lending act.

See: APR
Compare: Real Estate Settlement Procedure Act (RESPA)