Understanding Bootstrap 3 Grid System

Bootstrap 3 introduces a new grid system, with four tier of grid classes (phones, tablets, desktops and large desktops). This allows us to create flexible and awesome layouts for each of our target devices. In this tutorial, we will be looking at: Understanding Bootstrap 3 Grid System. Bootstrap 3 introduces the responsive mobile first fluid grid system that appropriately scales up to 12 columns as the device or viewport size increases.