Ethereum, the second-largest cryptocurrency, has moved to proof-of-stake, reducing its energy requirements. The transition, which has been underway since 2016, won’t change much for the average Ethereum user, but it does keep miners out.
The switchover began on September 6, when the Bellatrix upgrade was activated. It is now complete after mining the Terminal Total Difficulty block, which triggered the Paris upgrade. The technical part is over; now we see what is happening.
Before the merger, Ethereum operated on proof-of-work, where computers around the world competed to solve puzzles so they could add a new block to the chain. This was quite energy inefficient as all of these miners were competing to solve the puzzle at the same time, but only one could win; all other energy was wasted. Proof of Stake, on the other hand, has validators who have pledged their Ethereum as collateral. If they misbehave, they will lose the Ethereum they have staked.