Put simply, your credit score is a numerical interpretation of your creditworthiness and is calculated based on a complex combination of all the information on your credit report over a 6-year period.
Yes ... we realise this might sound complicated. In simple terms it means an indication of how you look to lenders such as credit cards and loan providers.
Credit providers will make their own assessment of your creditworthiness based on how your credit history meets their lending criteria but generally speaking the higher your credit score the more likely you are to be accepted for the best credit deals and interest rates.