A scaling solution built on top of a Layer 1 blockchain that processes transactions off-chain while inheriting the security of the base layer. L2 types include optimistic rollups (Arbitrum, Optimism), ZK rollups (zkSync, StarkNet), state channels, and sidechains. L2s post transaction data or proofs back to L1 for finality.
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A scaling solution built on top of a Layer 1 blockchain that processes transactions off-chain while inheriting the security of the base layer. L2 types include optimistic rollups (Arbitrum, Optimism), ZK rollups (zkSync, StarkNet), state channels, and sidechains. L2s post transaction data or proofs back to L1 for finality.
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Layer 2 (L2) (layer-2) Category: Blockchain General Definition: A scaling solution built on top of a Layer 1 blockchain that processes transactions off-chain while inheriting the security of the base layer. L2 types include optimistic rollups (Arbitrum, Optimism), ZK rollups (zkSync, StarkNet), state channels, and sidechains. L2s post transaction data or proofs back to L1 for finality. Aliases: L2 Related: Layer 1 (L1), Rollup
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The base blockchain network that provides consensus, data availability, and execution. Bitcoin, Ethereum, and Solana are Layer 1 blockchains. L1s define the core protocol rules, security model, and native token. Scalability limitations on L1 have driven the development of Layer 2 solutions that inherit L1 security.
A Layer 2 scaling technique that executes transactions off-chain, bundles them, and posts compressed data back to L1. Optimistic rollups assume transactions are valid and use fraud proofs for disputes (7-day challenge period). ZK rollups generate cryptographic validity proofs for every batch. Rollups inherit L1 security while providing 10-100x throughput improvement.
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The base blockchain network that provides consensus, data availability, and execution. Bitcoin, Ethereum, and Solana are Layer 1 blockchains. L1s define the core protocol rules, security model, and native token. Scalability limitations on L1 have driven the development of Layer 2 solutions that inherit L1 security.
Scaling and programmability solutions built on top of Bitcoin's base layer that extend its functionality while inheriting some degree of Bitcoin's security. Major approaches include the Lightning Network (payment channels), Stacks (smart contracts via Proof of Transfer), Liquid Network (Blockstream's federated sidechain), and ZK-rollups like Citrea (using BitVM for settlement). These solutions address Bitcoin's limited throughput (~7 TPS) and restricted scripting.
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The base blockchain network that provides consensus, data availability, and execution. Bitcoin, Ethereum, and Solana are Layer 1 blockchains. L1s define the core protocol rules, security model, and native token. Scalability limitations on L1 have driven the development of Layer 2 solutions that inherit L1 security.
A Layer 2 scaling technique that executes transactions off-chain, bundles them, and posts compressed data back to L1. Optimistic rollups assume transactions are valid and use fraud proofs for disputes (7-day challenge period). ZK rollups generate cryptographic validity proofs for every batch. Rollups inherit L1 security while providing 10-100x throughput improvement.
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A distributed, append-only ledger that records transactions in cryptographically linked blocks. Each block contains a hash of the previous block, forming an immutable chain. Nodes in the network maintain copies of the ledger and reach agreement through consensus mechanisms. Blockchains enable trustless, decentralized record-keeping without a central authority.
The protocol by which nodes in a distributed network agree on the current state of the ledger. Common mechanisms include Proof of Work (Bitcoin), Proof of Stake (Ethereum, Solana), and BFT variants. Consensus ensures all honest nodes converge on the same transaction history despite potential network delays or malicious actors.
A consensus mechanism where validators are selected to produce blocks based on the amount of cryptocurrency they have staked (locked) as collateral. PoS is energy-efficient compared to Proof of Work. Misbehaving validators risk losing their stake (slashing). Solana, Ethereum (post-Merge), Cosmos, and Cardano use PoS variants.
A consensus mechanism where miners compete to solve computationally expensive puzzles to produce blocks and earn rewards. PoW provides strong security (51% attack resistance) but is energy-intensive. Bitcoin and pre-Merge Ethereum use PoW. The difficulty adjusts to maintain target block times regardless of total network hash power.