If you have several student loans with different interest rates, you can consolidate everything into a single new loan with one interest rate. Juggling multiple loan payments can be difficult to keep up with, especially when you have multiple lenders. Not to mention, some student loan servicers buy and sell loans, so you could wind up paying different lenders than the original servicer that you used.
This will allow you to have all your student loans in one place so you can be more organized and track your progress better.