In September 2022, Ethereum replaced its energy-intensive proof-of-work mining with proof-of-stake, an event known as the Merge. Validators now secure the network by locking up ETH as collateral instead of competing with computing power.
What changed
Block validation moved from miners running specialized hardware to validators who stake at least 32 ETH. This cut Ethereum's energy consumption by roughly 99.9%, since there is no more computational race to win.
What did not change
Transaction fees, gas mechanics, and the execution layer where smart contracts run were not altered by the Merge itself. Users interacting with dApps did not need to change anything about how they use the network.
Why it mattered
Proof-of-stake lowered the barrier tied to energy costs and set the stage for further scaling upgrades, since the consensus layer redesign was a prerequisite for changes like sharding-related data availability improvements.
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