Interest is the amount you’ll have to pay back on top of the principle. It’s the money you’ll pay to the institution that lends you the money. It is really important to compare the interest rates offered from different financial institutions. The offer that financial institutions make to you is based, partly, on your credit scores but that doesn’t mean that all financial institutions will offer you the same deal. Saving a percentage point, or two, could end up saving you thousands of dollars over the lifetime of your loan.