Student loan debt consolidation is similar to other types of debt consolidation -- borrowers can combine multiple student loans into one for new terms and a potentially lower interest rate.
However, student loan debt consolidation differs depending on whether you have federal loans or private loans. If you have federal loans, consolidation can only occur through the Direct Loan program, for a new rate of the weighted average of all your loans, rounded to the nearest eighth.
You cannot consolidate private student loans. However, you can refinance your loans (both private and federal) into one brand-new loan. Keep in mind that debt consolidation is a loan combination, while refinancing is simply changing the terms on a debt obligation.