https://www.siliconvalley.com/2022/08/14/who-owns-your-credit-score-not-you/

Credit agencies know a lot about Americans. The agencies accumulate information, such as Social Security numbers, birthdays, how much savings people have, how much debt they’re in and how late they pay their bills.

That data is boiled down to a number ranging from 350-800 that estimates the risk of loaning someone money. It can determine the interest rates they pay and whether they get credit at all.