im waiting for someone to explain this.
So that's what it is! :O I've always wondered, thank you for the nice explanationThat's the main menu. From there, you can choose to play Singleplayer or Multiplayer. You can also change the options or texture pack for the game. There's also a button to view a list of installed mods. Or, you can quit. It's pretty handy. There's even a mod for it called VoxelMenu that makes it look different.