When you’re hiring someone for a job, the best choice is probably a person who has a reputation for doing similar jobs well in the past. Although someone without any established reputation is better than someone with a bad reputation, he’s still something of a gamble – you have no special reason to think he won’t perform the job well, but no reason to believe he will, either.
Credit history follows the same principle. It’s basically a record of how you’ve used credit in the past. How much do you owe right now? Have you made your credit payments on time? Have you had any financial problems? In credit as in anything else, a long history of good behavior is a great asset because it inspires trust. For example, a bank may be more inclined to let you take out a loan if you have an excellent credit history; if you’ve repaid your debts in a timely manner in the past, odds are you’ll deal with their loan in the same way.