Fixed interest rates stay the same over the life of the loan. Your interest rate will be determined by several factors when you apply, most importantly your credit history and that of your cosigner, if applicable.
Your interest rate options will be presented to you during the application process, at which point you can choose between a specific variable interest rate and specific fixed interest rate.
With prevailing interest rates at historic lows, some private lenders offer rates that are significantly better than a high-rate federal loan.
This is particularly true for grad school borrowers who use unsubsidized Direct loans and Graduate PLUS loans to finance their education.
In the event of the death or total and permanent disability of the borrower, the loan can be forgiven and the cosigner won’t be responsible for repayment.