Your credit score is one of the most important factors when determining how qualified you are for a loan. Credit card companies use your credit score to determine things like the interest rate that they charge you, how much you are allowed for a cash advance and how much your total credit limit will be.
Your overall credit rating takes many things into account. Your income level, how many on-time payments you have made in the past and your total debt level are all important factors. Many credit card companies offer cards to various credit ratings, even bad credit. This allows those with credit problems in the past to rebuild their credit rating over time by making timely payments.