There are different academic versions - some are individually licensed to the user, at an educational discount, and some are volume-licensed to the institution. Generally, the former cost more, but you can continue to use them after you leave, while the latter costs you as a student almost nothing, but technically the license is invalid after you leave the school. Also, the first most likely requires activation, just like other individual copies, and the second is "pre-activated" or doesn't otherwise require activation, like most site-license/VLK versions.
Of course, the actual license that you get and MS negotiated is what matters, I'm just mentioning the two most common cases that I've read about.