It is absolutely free to download and use.
It is a front-end framework used for easier and faster web development.
It includes HTML and CSS based design templates for typography, forms, buttons, tables, navigation, modals, image carousels and many others.
It facilitates you to create responsive designs.
Why use Bootstrap
Following are the main advantage of Bootstrap:
It is very easy to use. Anybody having basic knowledge of HTML and CSS can use Bootstrap.
It facilitates users to develop a responsive website.
It is compatible on most of browsers like Chrome, Firefox, Internet Explorer, Safari and Opera etc.
What is a responsive website
A website is called responsive website which can automatically adjust itself to look good on all devices, from smart phones to desktops etc.
What Bootstrap package contains
Scaffolding: Bootstrap provides a basic structure with Grid System, link styles, and background.
CSS: Bootstrap comes with the feature of global CSS settings, fundamental HTML elements style and an advanced grid system.
Components: Bootstrap contains a lot of reusable components built to provide iconography, dropdowns, navigation, alerts, pop-overs, and much more.
Customize: Bootstrap components are customizable and you can customize Bootstrap's components, LESS variables, and jQuery plugins to get your own style.