Scrolling means the user can move the displayed content with a finger swipe and display content outside the field of view. You can set vertical and horizontal scrolling in Purple DS apps.
The basic requirement for this is the element size is smaller than the content size. If there is no difference between these settings, then scrolling can not be enabled.
You can activate scrolling in the side menu (gearwheel) with "scroll horizontally" or "scroll vertically".
Furthermore, you can hide the scrollbar on devices by using the "Hide vertical scrollbar" and "Hide horizontal scrollbar" settings.
The "Paging Enabled" function causes the page on a mobile device to "snap into place" after browsing or scrolling through it. This function, for instance, is helpful in an image gallery with images of the same size. The user can scroll horizontally through the image gallery and images will always snaps to the image.