A background check is like a detective finding out information about you. People do background checks to see if you did something bad in the past, or if you've done good things. It helps them decide if they want to do business with you or hire you. They look at things like criminal records, your credit score, where you've lived and worked, and other details about you. They might also do a background check to make sure your identity is real and accurate. Background checks are done for things like jobs, mortgages and rental apartments.