A credit score determines your worthiness in borrowing money and repaying it starting at the age of 18. A credit score ranges from 300-850, where 850 is a really good score while 300 is a horrible score. Your credit score is based on your credit history which consists of several accounts, level of debt, and your repayment history. Companies use your credit score to determine the likelihood you will repay the loans you borrow. You should keep a high credit score because it allows you to easily borrow money so you could by a house, car, etc. You can get lower interest rates which means less money in the end. By having a bad credit score you will have a hard time buying things you want. Making companies not wanting to let you borrow money. To improve your credit score you can pay your bills on time, don't close credit cards, or up your credit line.