Material Design

Material Design is a new design language developed by Google, and first announced at Google I/O 2014. Material Design attempts to create a new cleaner design by relying upon grid-based layouts, responsive animations and transitions, padding, and depth effects such as lighting and shadows. During a demonstration of Material Design, Google put a heavy emphasis on the animation side of things, stating that in Material Design, all transitions should be animated.

Products Using Material Design
During its announcement, Google used the Android L preview to demonstrate the appearance of the new design language, as the entire operating system was redesigned to fit the new style. Since then, Google Drive, including Docs, Sheets, and Slides have all been redesigned to fit the new style. There have also been modifications made to many other products, as well as many modifications expected in the future. In addition to these redesigned services, many products already featured designs similar to the new language. Material Design was an extension of Google's design philosophy in products such as Google Now, Google Play, and Google+.

Source

 * Official Site