A credit report is a statement that has information about credit activity and credit history. This report tracks your performance with credit like new accounts, payments, and credit utilization. There are three credit bureaus: TransUnion, Experian, and Equifax. All three of these bureaus have multiple types of score models (example: FICO Score) that create a rating that lenders utilize to determine your credit worthiness.
Lenders use these reports as one of many tools to determine if they should or should not lend to you. Your individual credit score will vary depending on the bureau and score model your lender chooses to use. Often credit unions will look at this information but also consider your past relationship with them to provide more flexibility based on your individual situation.