Interest rates refer to the amount a lender charges a borrower in return for the privilege of borrowing money. This figure is generally expressed as a percentage of the principal. For example, if the interest rate on a $1,000 loan is 5 percent per year, and you want to pay off the loan in full at the end of a year, you would pay $1050: the $1000 you borrowed, plus $50 in interest. When you put money in a deposit account, you're essentially "loaning" money to the bank, so the bank pays you interest.