Layer 1 (L1)

A Layer 1 is the base-level blockchain — the original, self-sufficient network that handles everything on its own: processing transactions, reaching consensus on which transactions are valid, securing the ledger, and storing the final record. Bitcoin and Ethereum are the most famous examples, but Solana, Avalanche, and BNB Chain are also Layer 1 blockchains. When people talk about “the blockchain,” they are almost always referring to a Layer 1.

What makes a Layer 1 distinct is that it does not rely on any other blockchain to function. It has its own native currency, its own set of validators or miners, and its own rules for how blocks are produced and confirmed. All the security guarantees and decentralization properties of a blockchain ultimately flow from the Layer 1, which is why it is also called the “settlement layer” — it is where transactions find their final, permanent home. The challenge is that Layer 1 blockchains face a fundamental tension between decentralization, security, and speed, which has motivated the development of Layer 2 solutions built on top of them.

Example: Think of a Layer 1 blockchain like a country’s official land registry — the authoritative record of who owns what property. It is slow, formal, and requires careful process, but it is the ultimate source of truth. Everything else — contracts, sales agreements, temporary arrangements — ultimately gets recorded and settled there.