Both Ebooks on EBSCOhost and ProQuest's eBook Central require the use of this helper software if you wish to "check out" and read an e-book offline. 

Adobe Digital Editions is a free program that is different from Adobe Reader.

See the links below for the steps to download and install Adobe Digital Editions. 

Pro tip: If you read the book online, you will not need to download and configure Adobe Digital Editions.