Epoch
A fixed period used to organize a blockchain's operations — validator duties, reward cycles, and finality checkpoints.
An epoch is a defined time window (measured in blocks or slots) that structures a chain’s operations. On Ethereum, an epoch is 32 slots (~6.4 minutes) and serves as the cadence for validator committee assignments, reward and penalty accounting, and finality checkpoints.
Epochs matter to users in concrete ways: staking rewards and slashing are often reconciled per epoch, and unstaking or activation queues are measured in them. The concept appears across many Proof of Stake designs as the fundamental unit for organizing who does what and when — the heartbeat that turns continuous block production into orderly, accountable cycles.