Responsive web design, an USP that companies are using nowadays.
What is Responsive web design ?
Responsive Web Design also known as RWD is a concpet used to develop websites
which provides easy navigation, smooth and optimal viewing experience to the users.
The development involves lot of terminologies from CSS3 especially media library. Media library allows to use different types CSS depending upon the device. It can be run on desktops, laptops, tablets, mobile phones.
Referrence : http://en.wikipedia.org/wiki/Responsive_web_design