What is Validator?
A validator is a node in a Proof of Stake network that has locked the required stake to participate in consensus. Validators take turns proposing blocks and attesting to others' blocks; honest behaviour earns rewards, misbehaviour can be slashed.
Why Validator matters
Understanding Validator is part of building a solid mental model of how Bitcoin, blockchain and Web3 systems actually work. Concepts in the Concepts category sit at the foundation of the broader stack — get them right and the rest is far easier.
Learn this interactively
Reading the definition is a start. ZeroToBlock teaches concepts like Validator through hands-on, browser-based simulations. Build the mental model by actually using it:
- Bitcoin 101 — interactive fundamentals course
- Bitcoin Proof of Work — mining, hashing and consensus
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Related terms
- Proof of Stake — A consensus mechanism where validators stake capital instead of burning energy.
- Staking — Locking tokens to secure a network and earn rewards.
- Slashing — Destroying part of a validator's stake as punishment.
More concepts terms
- Decentralization — Distributing control across many independent participants.
- Atomic Swap — Trustless cross-chain trade using hash time-locked contracts.
- Bridge — A protocol that moves assets or messages between chains.
- Byzantine Fault Tolerance (BFT) — A system that works even when some nodes lie or fail.
- Layer 1 (L1) — A base blockchain network with its own consensus.
- Layer 2 (L2) — A scaling network that settles to a Layer 1.
- Rollup — An L2 that posts transaction data to L1 for security.
- Optimistic Rollup — A rollup that assumes validity, with a fraud-proof challenge window.
Keep exploring
Continue with the full blockchain glossary — 136 terms in total — or read the developer blog and FAQ for deeper context.