When you purchase the print format of a Cognella textbook, we provide you with partial digital access of up to 30% of the materials so you can read and study while print materials are shipped to you. The partial digital content can be accessed in the My Digital Materials section of your store account and can be viewed in any PDF software such as your browser, Adobe Reader, Apple Preview, etc. Adobe Reader is a free application to view PDF files. You can download and install the application here: https://get.adobe.com/reader/.