For a blockchain to make progress, new blocks must be created and added to chain. Who has the right to make these new blocks? In a Proof-of-Work system, block producers (aka miners or validators) compete for this right by expending computing power to solve random cryptographic puzzles. The winner gets to create the next block, and earns some reward for doing so. In this paradigm, the more computing power a miner has, the more likely they are to create the next block. By contrast, PoS systems revolve around the idea that the more coins a block producer has, the more likely they are to create the next block.