What is Genesis block?
The first block of a blockchain, the anchor every later block traces back to.
The genesis block is block zero. Everything else builds on it, so the chain's identity is fixed by that first block rather than by the network name it advertises.
It matters in practice when someone launches a fork or a copy: two chains with different genesis blocks are genuinely different networks, whatever their ticker says.
Related terms
- ForkBasics
A change to a blockchain's rules; a soft fork is compatible, a hard fork splits the chain.
- Consensus mechanismBasics
The rule that decides which version of a chain's history is correct — proof of work or proof of stake.