The Void occupies the space below the bedrock layer. It is a vast, pitch-black space with smoke particles visible around the player.
Falling into the Void in either Survival or Adventure mode, difficult given that bedrock is unbreakable normally, guarantees death approximately 5 seconds after entry under normal circumstances. On Creative and Spectator mode, it is possible to fly out of the Void after entering it, but Void damage can and will kill players in these modes - only of the only two methods of doing so. All mobs suffer the same effect upon entering the Void as players. It is possible to stay alive for longer if you either have a large amount of health, or a high rate of health regeneration.
The air is filled with smoke particles, and light does not pervade into the area from light sources above y=0. Water and lava cannot flow into it, and instead are halted as though there is a block present. No block can be placed in the Void (on the bottom of the final layer of bedrock).