Why Bootstrap?

Twitter Bootstrap is a front-end toolkit to rapidly build web applications. It is a framework that uses some of the latest browser techniques to provide you with stylish typography, navigation, buttons, tables, etc. One of the primary changes in Bootstrap 3 is an emphasis on Mobile-First responsive design. The goal is to elevate the mobile experience to a first-class citizen of the design process, because several billion mobile users is quite a large market to tap into. So, sites built with the current Bootstrap version target mobile devices and scale for larger screens depending on screen size.
This Bootstrap layout was made @Bootply. Bootply is a HTML, JavaScript and CSS editor app built just for Bootstrap. Bootply enables developers to easily apply the Bootstrap Framework to their projects using a beautiful hand-coding interface. The browser-based Bootply editor lets developers select and paste Bootstrap friendly code snippets. Bootply can be used to test, manage and share any Bootstrap code, from small snippets to entire Bootstrap-ready themes. Find it at http://bootply.com
The sizing "grid" is not the only aspect of responsive design. Making images and media object scale correctly is another consideration for responsive developers. Go ahead and shrink your browser's width to see how the HTML elements and images respond as the width of the viewport changes.

Bootstrap Template

1 CSS Grid
This demonstrates applying float right only on small devices.
2 Non-Stacking
For columns that never stack use the Bootstrap 3 `xs` grid size.

Bootstrap Layout

3 Responsive
Resize the browser or viewport width to see how this stacks up.
4 Multiple Sizes
The powerful Bootstrap grid comes in 4 sizes for multiple devices.