In plain English
What Layer 1 means
A layer 1 is the underlying chain that participants validate directly under that network’s rules. It records its own blocks and determines which transactions are valid. The term is often used when comparing a base chain with a layer 2 system that processes some activity separately and then anchors or settles information on the base chain. Not every connected chain is a true layer 2.
Why it matters
The layer 1 determines core trade-offs such as its consensus mechanism, transaction capacity, fee market, and finality rules. When moving assets or using an application, it is important to identify which network actually holds the asset and what security assumptions apply. A bridge, sidechain, or app can introduce risks beyond the layer 1 itself.
Example
A user sends ETH on Ethereum Mainnet, so the transaction is executed and settled on Ethereum’s layer 1. If the user instead moves ETH to a separate scaling network, that network may process later transfers more cheaply. Returning or resolving those transfers can depend on the scaling network’s design, bridge, and Ethereum settlement process.
Quick answers
Common questions
Is a layer 1 the same as a cryptocurrency?+
No. A layer 1 is the underlying blockchain network. Its native cryptocurrency may be used for fees, staking, or incentives, but tokens issued by smart contracts on that chain are not themselves layer 1 blockchains.
Are all networks connected to a layer 1 considered layer 2s?+
No. The label depends on how the network works and what it inherits from the base chain. Sidechains, validiums, and bridges can have different validator sets, data arrangements, or trust assumptions from a layer 2.
Sources