Hard Fork
A blockchain protocol change that's not backward-compatible, potentially splitting the network into two separate chains.
In-Depth Explanation
Hard forks change consensus rules in ways that old nodes can't validate. If the community disagrees, both chains may persist (Ethereum/Ethereum Classic after The DAO hack, Bitcoin/Bitcoin Cash over block size). Coordinated hard forks upgrade the entire network; contentious forks create competing chains with shared history up to the split.
Related Terms
Soft Fork
A backward-compatible blockchain upgrade where new rules are stricter than old rules.
Consensus Mechanism
The method by which a blockchain network agrees on the current state of the ledger and validates new transactions.
Blockchain
A distributed, immutable ledger that records transactions across a network of computers using cryptographic linking.
More in Infrastructure
View all →Gas Fees
Transaction fees paid to validators/miners for executing operations on a blockchain.
Gwei
A denomination of Ether equal to one billionth of an ETH, commonly used to express gas prices.
Layer 2
L2Scaling solutions built on top of a base blockchain (L1) that process transactions off-chain while inheriting L1 security.
Layer 1
L1The base blockchain that provides security and consensus, such as Ethereum, Bitcoin, or Solana.