The Wii U was the first Nintendo console to support HD graphics. The system's primary controller is the Wii U GamePad, which features an embedded touchscreen, directional buttons, analog sticks, and action buttons. The screen can be used either as a supplement to the main display or in supported games to play the game directly on the GamePad. The Wii U Pro Controller can be used in its place as a more traditional alternative. The Wii U is backward compatible with all Wii software and accessories. Games can support any combination of the GamePad, Wii Remote, Nunchuk, Balance Board, or Nintendo's Classic Controller or Wii U Pro Controller. Online functionality centers around the Nintendo Network platform and Miiverse, an integrated social networking service which allows users to share content in game-specific communities.