Proof-of-History (PoH)
One of the main features of the system is a cryptographic clock, which enables the determinism of the order of the events. To achieve the gas of the exceptional network throughput, Solana combines Proof-of-History (PoH) with Proof-of-Stake (PoS). While PoS is used to secure the network and keep it energy efficient, PoH acts as the source of time that records the transactions that happened before consensus.