Layer 1
The base blockchain itself, where transactions settle and security lives, before any add-on networks built on top.
Layer 1 is the foundational chain, like Bitcoin, Ethereum, or Solana. It runs its own consensus, validates transactions, and provides the security everything else inherits. When people say 'on-chain,' they usually mean here.
The limit is throughput. A decentralized layer 1 can only process so many transactions per second, which is why fees spike under load. Layer 2 networks exist to take work off the base layer while still settling back to it.
Related terms
A separate network built on top of a base chain to process transactions faster and far more cheaply.
BlockchainA shared digital ledger that records transactions in linked batches, copied across many computers and hard to alter.
RollupA scaling method that batches many transactions off-chain and posts a compressed proof or record to the base layer.
Consensus MechanismThe rules a decentralized network follows to agree on one valid history without trusting any central party.