Scores under 500 = Bad Score.
Scores 500 - 600 = Poor Score.
Scores 600-650 = Fair Score.
This usually results from late payments, collections and charge- offs. You will most likely be charged the highest interest rate allowed by law in your state or you could be turned down completely.
Scores 650-700 = Good Score.
As long as your debt to income ratio is low you will be approved and will likely pay a lower interest rate on your loan.
Scores 700 + = Great Score.
You are considered a "prime borrower" and will be able to obtain favorable financing terms.