Every front-end framework described here is based on the responsive grid. Your content is arranged into rows and columns, which adjust themselves based on screen size.
For instance, if you have three columns of information on a large screen, they may become one column on a small screen.
The responsive grid makes your site look good on desktop computers, tablets, and phones.
Here is an example of the grid in action, thanks to our friends in Sweden:
Notice that the site’s columns shrink in the transition from desktop to tablet, and become a single column on a phone.
More and more, people expect content to look good on all devices. Sometimes, a separate “mobile” web site or app is a good approach. However, a responsive web site is often the clearest path, and frameworks make it easier to implement.