𧱠Layer 1 Layer 1
The base blockchain network itself β the chain that validates, runs, and finalizes its own transactions without relying on any other network. Bitcoin, Ethereum, and Solana are Layer 1s, and everything else is built on top.
π The simple version β the foundation of a house
Picture a house. The foundation holds everything up: every room, every floor, every appliance depends on it. A Layer 1 is that foundation for a blockchain. It is the base network that does the core work itself β it decides how blocks are made, checks that every transaction is valid, and keeps the whole thing secure. Bitcoin, Ethereum, and Solana are all Layer 1s. The apps, the tokens, and the faster Layer 2 networks all sit on top of one.
π What makes a chain a Layer 1?
A Layer 1 settles its own transactions with finality, on its own chain, and answers to no other network for security. It does that through its own consensus mechanism β the rule for how the network agrees on what is true. Bitcoin uses Proof of Work; Ethereum uses Proof of Stake. Each Layer 1 also has a native coin (BTC, ETH, SOL) that pays the network's fees and helps keep it secure.
βοΈ The scalability trilemma β why you can't have it all
Beginners often assume a bigger, faster chain must be the best one. It is not that simple. A Layer 1 juggles three goals, and there is a hard trade-off between them.
| Property | What it means |
|---|---|
| π Security | How hard it is for an attacker to cheat or rewrite the chain |
| π Decentralization | How spread out control is, so no single party runs the show |
| β‘ Scalability | How many transactions the chain can handle quickly and cheaply |
π The scalability trilemma says a chain can strongly optimize for only two of these three at once. Push speed up and you usually give up some security or decentralization. Fast is not free.
π¦ How Layer 1s try to scale
When a Layer 1 gets popular, it can slow down and gas fees can climb. There are a few common ways a Layer 1 tries to handle more traffic:
- π¦ Bigger blocks β fit more transactions into each block
- π A different consensus mechanism β change the rule for agreeing on blocks to a faster one
- 𧩠Sharding β split the chain into parallel pieces that process work side by side
- ποΈ Push work up to a Layer 2 β handle transactions on a network built on top, then settle back down
β FAQ
- Is a Layer 2 a different chain that competes with a Layer 1?
- No. A Layer 2 is built on top of a Layer 1 and leans on it for security and final settlement. Bitcoin's Lightning Network and Ethereum's rollups are Layer 2s β they speed things up, then settle back down to the Layer 1 underneath them.
- Is a bigger or faster Layer 1 automatically better?
- Not automatically. The scalability trilemma says a chain can strongly optimize for only two of three properties at once: security, decentralization, and scalability. Pushing speed up often trades away one of the other two, so fast is not free.
- What is the native coin of a Layer 1 for?
- It pays the network's fees and helps secure it. BTC, ETH, and SOL are the native coins of their Layer 1s. You spend a little of the native coin to get a transaction processed, and on Proof-of-Stake chains it is also staked to keep the network honest.