A credit freeze is, as the name implies, a freezing of your credit report at your request whereby no one can have access to your credit report even if they have your Social Security number and other personal information about you. You control access to the credit report through a special PIN that you choose. Thus, even if someone was able to steal your Social Security number, they could not parlay that into access to your credit report to be able to purchase things or set up accounts using your name. If you need to thaw out your credit report at such times as you want to apply for credit in the future, it is an easy procedure to do so using your PIN; then, after your new credit has been established, you can freeze your credit report again.
Having your credit frozen will not affect your ability to get your annual free credit reports from each of the three major credit-reporting agencies Equifax, Experian and TransUnion. It is important to put a credit freeze on your credit report at each of the three major credit reporting agencies. Here are the links to each of them where you can go to freeze your credit.