EndNote Online is both a web-based version of EndNote (with fewer features) and a method for accessing and sharing EndNote libraries created and managed with the full, desktop version of EndNote.
EndNote Basic - EndNote Online only. "Perfect for the new-to-research and writing student." Direct Export and Cite While You Write work, but EndNote Basic stores fewer references and PDfs, and offers fewer output styles. EndNote Basic is free.
EndNote X9 - The desktop version. All the features of EndNote Basic, plus find full text, search and annotate PDFs, and create new output styles. Compare EndNote Basic and EndNote X9.
EndNote Sync - Sync libraries among desktops, ipads, and online. Also share an EndNote library or group by syncing with up to 100 other EndNote users.
Additional Training Materials (PDF and Video)