Different reporting agencies have different methods of measuring your score. They all take in to account how much debt you have, your payment history, how long you've had the accounts, and other factors. The importance of each can change slightly between reports so small differences are not a problem or something you should worry about.
However, if there are large differences in scores you need to research the factors and see where the difference is. One score may show a late payment from 10 years ago while another score will only look 7 years back. It is important to understand the factors that go into your score as well as which parts apply to you.
