Adobe Acrobat 7 Professional - Manual (Page 712)

About Digital Editions
Adobe Digital Editions (eBooks) are PDF files that have been packaged by the Adobe
Content Server to protect the copyright of the author or publisher. Digital Editions are
typically bought from online bookstores, borrowed from online lenders, or exchanged
among users. You can also subscribe to periodicals in digital edition format. To read a
Digital Edition, you must have a license to open and read the Digital Edition (generally
provided by the seller or lender), and you must activate Acrobat.