Never heard of "student fares." I did a quick search on Google and came across a site called studentuniverse. They have on their website "StudentUniverse negotiates with United Airlines to get special discount fares for students. College students are eligible to purchase discounted flights on United Airlines to Europe, Asia, and the South Pacific." Tried to dig a little more and seems like they only have discounted travel to Europe, Asia, and outside U.S.
I did not look to see if the airfare was actually discounted, but seems like no discount within U.S.