I want to start paying off my student loans while I'm in school but I'm a little confused?

So I logged into fafsa.gov to see my loan status, it said 26,800. Then I logged in through sallie mae and it said 26,800 +1000 interest accrued. I guess Im just a little confused on the difference. Why do I have a balance with fafsa and one with sallie mae, are they two seperate loans? And if so how do i begin to pay both back, thanks