Solana is a permissionless network protocol with the parallel smart contract processing functionality.
For consensus, Solana uses a combination of proof-of-stake to secure the network and the proof-of-history mechanism to synchronize the network state.
Validators on the network stake SOL to get the right to confirm blocks in assigned time slots.
To get an assigned time slot, validator nodes use the sequence of hashed events that each of them maintains, which is called proof of history.
- Solana documentation: More on Proof of History (opens new window)