Answer:
An auto loan and a personal loan have the similarity in that they are both loans. Personal loans can be secured or unsecured. Secured meaning that there is some form of collateral to back up the loan in the event that the borrower defaults. Unsecured has no collateral which usually translates into higher interest rates due to the added risk on the lender. An auto loan may carry a lower interest rate due to it being secured; if you don't make the payments you lose the car.