What is Google’s Material Design?

Material Design
Material design is a concept of visual language developed by google. It's include 3D dimension of object, soft shadow form all angles and define the layer position in the design by shadow.

Google has just revealed a new design language for Android, Chrome OS, and the web. The new look — which was first previewed in a Google+ app update last month — includes splashes of color, refreshed iconography, typography, and a more consistent interface hierarchy.

You can get a little taste of Material Design for yourself over at Google's Polymer Project, where one of the web apps Duarte demoed on stage is live for anyone with a Chrome browser to explore.