Bootstrap is the most popular HTML, CSS, and JavaScript framework for developing responsive, mobile-first web sites.

It is a free front-end framework for faster and easier web development. It includes HTML and CSS based design templates for typography, forms, buttons, tables, navigation, modals, image carousels and many other, as well as optional JavaScript plugins. It also gives you the ability to easily create responsive designs

For Reference – http://www.w3schools.com/bootstrap/

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