Distiller is a kinda 'plugin' that will allow you to 'print' or export PDF out from a lot of applications and not only Adobe. You can 'print' out PDF from MS Word, Excel..that kinda thing.

Acrobat Reader.. well, if it comes with Distiller then it should be the pro version. There are 2 versions presented by Adobe. I'm not too sure of the exact capabilities of Acrobat Reader coz half the time I only use it for reading PDFs.