You may have a few e-textbooks available to you via the DLE, but the library also purchases e-books wherever possible. These are designed to be read online although some will also let you download for a period of time.
The advantage of an e-book is that as long as you have access to the internet you will be able to access them wherever and whenever you want, in many cases you can make notes on them, highlight text, and bookmark pages.
Searching on Primo will discover both print and e-books.
From Primo, click on the image, the title or 'Online access' and then the e book link, to open up the e-book:
An increasing number of e books are now available to download and read offline, sometimes a chapter at a time, sometimes the whole book for a limited time period.
Unlimited access means that any number of people can access the book at the same time
Multiple access/copies means that we have a number of licenses per year, in the range of 200 - 400
1 copy/single user license means that only one person at a time may view the e-book - if you can't get into the book, try again later.