What is 18grid?
18grid is an 18-column fluid CSS grid. It is a tool for building responsive layouts quickly, easily, and with minimal effort. You don't need to worry about rearranging and resizing your layout for different screen sizes; 18grid does this for you automatically.
18grid is a percentage-based grid system, which means that it will adapt to all screen resolutions, from mobile all the way to widescreen monitors. 18grid is designed to take advantage of the full screen real estate available on large widescreen monitors, while still looking great on small mobile device screens.
For better understanding of how 18grid works, please have a look at the grid reference.