Responsive web design makes your web page look good on all devices. It uses only HTML and CSS and is not a program or a JavaScript. Web pages can be viewed using many different devices: desktops, tablets, and phones. Your web page should look good, and be easy to use, regardless of the device. Web pages should not leave out information to fit smaller devices, but rather adapt its content to fit any device:

rwd desktopDesktop

rwd phonePhone

rwd tabletTablet

If you are using a laptop or larger screen right now, you can try it out by making your browser screen smaller and watch everything on the page move to fit into the smaller window. This is responsive web design.

Bootstrap is the most popular HTML, CSS, and JavaScript framework for developing responsive, mobile-first web sites and is completely free to download and use!