BootStrap is javascript framework which is used to develop responsive websites. BootStrap is also known as twitter bootstrap is developed by the developers at Twitter. This library is extensively used by the web developers and designers to create almost
irresistable content that looks good on all screen sizes.
Bootstrap is a free and open-source front-end web framework for designing websites and web applications. It contains HTML- and CSS-based design templates for typography, forms, buttons, navigation and other interface components, as well as optional JavaScript extensions. Unlike many web frameworks, it concerns itself with front-end development only. Bootstrap is the second most-starred project on GitHub, with more than 100,000 stars and 45,000 forks.
The Bootstrap adopted the famous grid system and continue to work with it since the 2.0 release. Starting with version 3.0,Bootstrap adopted a mobile-first design philosophy, emphasizing responsive design by default. With the great documentation
and large fan base you can easily find tutorials on this topic making it easier to start writing your bootstrap enabled. And the best part is that you only have to know simple html to get started.