// GLOSSARY -- BLOCKCHAIN & CRYPTO FUNDAMENTALS
What is Layer 1 (L1)?
A Layer 1 (L1) blockchain is the base-level network providing its own consensus, security, and execution — such as Ethereum, Bitcoin, or Solana — upon which L2 solutions and applications are built.
WHY IT MATTERS
Layer 1 is the foundation — the blockchain that validates transactions, maintains consensus, and provides security guarantees. When protocols 'launch on Ethereum' or 'deploy on Solana,' they're using L1.
L1s differ in architecture: consensus mechanism, execution model, throughput, finality time, and decentralization. These tradeoffs create the landscape of competing chains.
The trend: L1s increasingly serve as 'settlement layers,' providing security while delegating execution to L2 rollups. Ethereum leads this approach explicitly.
FREQUENTLY ASKED QUESTIONS
Which L1 is best?
Depends on requirements. Ethereum has the strongest ecosystem. Solana offers highest throughput. Bitcoin has most robust decentralization. Each makes different tradeoffs.
Do we need multiple L1s?
Debated. Multi-chain advocates say different chains serve different needs. Ethereum maximalists say L2 rollups provide sufficient diversity. A multi-chain world seems likely.
L1 vs L2 relationship?
L2s execute transactions off L1, posting proofs back for security. L1 is the security layer; L2 is the execution and scaling layer.