With proof of stake, validators don't race to solve cryptographic puzzles - they don't mine. Instead, they stake their own crypto assets in order to participate in consensus. This uses a tiny fraction of the energy of proof of work. It is also faster - which is important for applications that require speed and scalability.There are many variations of proof of stake. All involve participants staking tokens to determine who forms and validates the next block but some pick a staking validator at random while others preselect staking validators to decide on the contents of the block and its addition to the blockchain.Besides proof of work and proof of stake, there are many other methods - for example, proof of activity, proof of capacity, and proof of burn.