Network Upgrades

Ethereum changes through hard forks: coordinated upgrades that execution clients, consensus clients, validators, and apps all prepare for in advance. The point is not to surprise users, but to ship protocol improvements without breaking the chain's continuity.

The Merge mattered because it changed consensus without changing the contract universe sitting on top. Users kept the same addresses, tokens, and apps, but block production moved from miners to validators. That made later roadmap work possible without resetting the ecosystem.

Shanghai and Dencun were more targeted, but they changed user behavior in visible ways. Withdrawals made staking more credible, while blobs lowered the cost structure for rollups. That pattern is common on Ethereum: a fork may look abstract in the spec, yet quickly show up as new economics in wallets, exchanges, and L2 fee charts.