Bedrock

Bedrock is an unbreakable Block that is found at the bottom of the Overworld. It was added in TU1.

Usage
Bedrock is used to create a barrier between the Overworld and the Void, preventing Players from falling into the Void, dying, and losing all their belongings. It also completely surrounds the Nether, and it is serves as the End Gateway Portal to get back to the Overworld after the Ender Dragon is released.

Trivia

 * Prior to TU14, the bottom layer of Bedrock could not be broken in a world, even in Creative Mode.