Your credit report is a record of your personal credit history created by a credit bureau. Data contained in your credit report is used to generate your credit score. The three major bureaus that issue credit reports in the U.S. are Equifax, Experian, and TransUnion.
Your credit report accounts for all transactions you make in the world of credit. This could include opening a credit card, paying off a student loan, or events like hard credit inquiries. After collecting this information, the bureaus apply algorithms, like the popular FICO algorithm, to your credit history in order to calculate your credit score—this means that if you have any concerns about your credit score, you can go back to the source by checking your credit report. Because each of the bureaus obtain and report credit data differently, you might encounter slight differences between your three reports.
You're entitled to one free credit report per year from each of the three major credit bureaus, which you can obtain from a site such as https://annualcreditreport.com (and you can get your credit score for free at Credit Karma). If you're concerned about a negative credit event, such as a missed payment, don't worry: Many types of negative information are removed in 7 or 10 years.