In terms of functionality – nothing.

All Adobe Student Editions function exactly the same as the regular commercial versions. Also, when new versions of the program are released, you can pay the

same upgrade fee as a commercial user, and gain access to the new commercial version of the program.

As the commercial editions are quite pricey for many products, you can save a ton of dough purchasing the student editions.

However, there are three

main differences.

Commercial work – Adobe student versions do not license you to use your work for commercial gain. Although it is possible, and nearly untraceable, it is also illegal and therefore not advised.

Location of use – Adobe student editions may be used only on private computers. Additionally, they may only be installed on one computer.

Eligibility – You are eligible to purchase Adobe student editions only if:
You attend (full or part-time) any accredited university or college which grants degrees in two or more years.
You attend a public or private school full time.

You will be asked to provide proof of eligibility.

More details are located here.