I am new to bootstrap. I have gone through What is Bootstrap? and http://getbootstrap.com/.
As per my current understanding bootstrap is actually a CSS framework which helps us to achieve responsive design that fits all devices. Which internally means
1) Bootstrap has collection of ready-made CSS files which can apply straightaway to any web app.
2) It provides the modular way where we can structure the CSS files per device and apply it
What i did not get is this
Bootstrap is an HTML, JavaScript framework that you can use as basis for creating web sites or web applications.
What features bootstrap provides in terms of HTML and JavaScript apart from CSS and what is the role of them in responsive designing ?