A high-level explanation of Solana’s core innovationWhereas other blockchains require validators to talk to one another in order to agree that time has passed, each Solana validator maintains its own clock by encoding the passage of time in a simple SHA-256, sequential-hashing verifiable delay function (VDF). Solana does not use a VDF for randomness. Instead, each validator uses the VDF to maintain its own clock. Because each validator maintains its own clock, leader selection is scheduled ahead of time for an entire epoch.
Like Tendermint, the schedule for an epoch lasts for thousands of blocks. However, unlike Tendermint, the network never waits for a failed node. Each validator runs the VDF to prove that it has acquired its slot to transmit a block and validators. Each validator is compensated for doing so because the block producer receives a reward for producing a block.