What exactly is an unsubsidized Stafford Loan?

<p>I have a question related to this. My S has received 3 packages. All the schools have approx. the same tuition and R&B (after scholarships). One school offered a subsidized loan, one a unsubsidized loan and one is half sub and half unsub. </p>

<p>Does anyone have any idea why the packages are different? They all offered the same amount, the only difference is subsidized and unsubsidized. Can I ask the school that gave us the unsubsidized loan to change it to subsidized?</p>