The difference between grid and swipable is the way the images will be displayed(those images are actually the cover of a specific learning page inside the module).
With the grid view, you will have all images next to each other:
With the swipable, you are able to swipe in order to check all images:
The swipable mode is more user friendly when it comes to mobile phones. Therefore, keep that also in mind when choosing what is more appropriate for your app.