Here's a quick overview of the options when you're choosing a license for Delphi.
Choose an Edition
Delphi comes in three editions - Professional, Enterprise and Architect. In general, the Professional edition includes all the basics for building Windows apps, Web apps with some limitations, and database apps limited to local connectivity with a few databases. As you move up to the Enterprise edition you get expanded web and database development functionality plus UML modeling and some other higher end features. The main thing Architect adds is the ability to do database modeling and design with ER/Studio. You can find out more about the different editions of Delphi on the Delphi Product Editions page or see a very detailed feature-by-feature comparison in the full feature matrix PDF.
Choose a License Type
Embarcadero offers a few different license types for Delphi including Named User, Networked Named User and Networked Concurrent User. Individuals usually choose the single named user license. If a company has multiple users and wants to manage the licenses for those users within their network and transfer licenses between users without going through Embarcadero, they can do so with Networked licenses. Those licenses can either be named user licenses (each license assigned to a single named user) or they can be concurrent licenses (licenses are checked out from a pool of available licenses). There are also two choices of license servers to manage the licenses - either Embarcadero's "ELC" license server or FLEXnet. For more information to help you choose, see the Software Licensing Solutions page.
Academic licenses follow along the same types as above but with some minor differences. Academic discounts are available in most countries. That can include discounts on individual licenses for educators and students, classroom licenses (which are Networked Concurrent licenses managed with the ELC license server described above), and educational site licenses that can cover multiple products across an entire campus or school system. The options vary by country so it's best to contact your Embarcadero representative for all the details and they can help you or refer you to an academic partner that serves your area.