What is the difference between a Perkins Loan that is subsidized and one that is unsubsidized?

The main difference between a subsidized Perkins Loan and an unsubsidized Perkins Loan is that with a subsidized loan, the government pays the interest while the borrower is in school, during the grace period, and during deferment periods. With an unsubsidized loan, the borrower is responsible for paying all of the interest that accrues on the loan.