A slot is the fundamental time unit of the Solana blockchain. Each slot lasts approximately 400 milliseconds, during which one designated validator is responsible for producing a block. Slots are the granular building blocks of Solana epochs.

Not every slot results in a block — a validator may miss their slot due to downtime or network issues, resulting in a skipped slot. Skip rate is a metric for validator performance.

Solana's slot speed (approximately 2,500 slots per second at target) enables its high transaction throughput. Transactions submitted to the network typically confirm within one or two slots — under 1 second.