Inside story on the credit score and how it can rule your life

What's your score? No, this isn't a pick-up line. Every time you apply for a loan, an apartment or a credit card, companies contact credit bureaus like Experian and TransUnion to obtain your score -- your credit score that is. That number and your credit history can often times make or break a deal.

But what is this all-powerful number? Ann-Marie Murphy -- co-creator of Quizzle, a personal finance website that helps people manage their home, money and credit and is best known for giving users free credit reports and scores – explains the math and how it can affect your life.

What should people know about credit? I was surprised, for example, to hear employers are using your credit information to determine if you're a good hire.

"People need to learn that credit is not necessarily intuitive. The infamous example is closing a credit card account. You think it's the financially responsible thing to do. But it will ding your credit score because credit utilization is one-third of your score. That is how much credit you use compared to how much credit is available to you. It makes it look like you are using more of your available credit, which the credit score gods don't like. People have to understand that it is not intuitive.