Media queries allow you to apply the CSS differently according to the media type (type of device) and media features (viewport status). Previously, you were able to use the media type only and create websites with fixed layouts. However, smart phones, tablets, and other devices with various resolutions require a liquid layout. HTML5 now makes various characteristics and conditional defining possible, and can be used to implement responsive web design (RWD), which is a liquid layout that mainly reacts according to the device resolution.
Quote:
People ignore design that ignores people. — Frank Chimero