Documents stored in cloud storage can be downloaded for offline access use. This is especially helpful if you want to work on a document but will not have access to internet connection.
Download for Offline Access:
1. From the library view (tap the "+" in the top left corner to access library), Navigate to the document.
2. Tap the circle on the left of the document thumbnail so that a tick appears in the circle.
3. Tap the "..." at the bottom of the screen.
4. Tap "Download for Offline Access".