Minecraftia
Minecraftia is the name of the world.
According to lore it would not make sense, since the First Phase ended, and a complete new world was found. The Second Phase followed, but was destroyed later on. The Mayas ended the second phase by activating their Mayan phase temple which would make the planet burn. Logically, Minecraftia would be the name of the world the current phase is in, and all previous phases have been. However, according to lore, it seems more logical that the first phase is one world, the second phase is one world and the Third Phase is also a separate world. The first phase seems to be active still. The second phase has been destroyed and the third phase is still active currently.
Interesting pages: