In traditional use, your report is used to predict how promptly you'll pay your credit card bills. That score distills everything that credit bureaus know about your debts, such as how many years you've had credit cards, how much credit you use and how many times you've paid bills late. You don't know your score. It's released only to people who inquire about you.
Scores change as new information comes in.
You may get different scores from different bureaus, because of an error in your file. When you apply for a credit card or auto loan, a computer dials up your score to see if it makes that particular lender's cut. If not, you're probably dead. In general, credit scoring is a clear consumer plus, because there's no waiting while a lender checks us out. Snap approvals for good risks also will become more common among mortgage lenders.