Credit scores are used by lenders, including banks providing mortgage loans, credit card companies, and even car dealerships financing auto purchases, to make decisions about whether or not to offer your credit (such as a credit card or loan) and what the terms of the offer (such as the interest rate or down payment) will be. There are many different types of credit scores. FICO® Scores and scores by VantageScore are two of the most common types of credit scores, but industry-specific scores also exist.
While the FTC has tried to increase transparency, some websites offering “free” credit scores have found a way around those rules. If a website asks for your credit card before providing a score, expect to find a fee on your bill before too long. Of course, since there are resources to see this data for free, that's probably where you should start your search.
You can get one free credit report each year from each of the three nationwide credit bureaus. The website annualcreditreport.com is your portal to your free reports. (Note: when you leave that website and move to the company website to get your free report, the company will probably try to get you to sign up for costly and unnecessary credit monitoring services.)