Slot
Plain English
The smallest unit of time in Solana’s schedule (400 milliseconds). Each slot is assigned to a specific validator who can produce a block during that time. Like scheduled time slots in an appointment calendar - each validator gets specific slots to produce blocks.
Technical
Atomic time unit in Solana’s leader schedule, nominally 400ms. Each slot allocated to a single leader validator for block production. Slots numbered sequentially from genesis. Multiple slots can pass without blocks (leader offline/skipped). Leader schedule rotates deterministically based on stake weight. Critical for PoH verification and consensus timing.