Layer 1
In short A Layer 1 is a base blockchain, such as Bitcoin, Ethereum, or Solana, that orders, validates, and finalizes its own transactions with its own native coin.
A Layer 1, or L1, is a standalone blockchain that does not depend on any other chain for security. It has its own network of nodes, its own consensus rules, and its own native coin used to pay fees, such as BTC on Bitcoin, ETH on Ethereum, SOL on Solana, or BNB on BNB Chain.
Mechanically, an L1 does everything itself. Users broadcast transactions, validators or miners order them into blocks, and the consensus mechanism decides which blocks are final. Every full node stores the history and checks the rules, so nobody has to trust a single operator. The design choices made here, like block size, block time, and how validators are chosen, set the chain's speed, fees, and how decentralized it is.
For token holders this matters because the L1 is the foundation everything else sits on. A token issued on a chain inherits that chain's fees, uptime, and security. If the base chain halts, congests, or reorganizes blocks, every token on it is affected, no matter how good the project is. It also explains why the same project can trade under different contract addresses on different L1s: each chain is a separate ledger.
When looking at a token, check which L1 it actually lives on and that your wallet and exchange support that network, since sending coins on the wrong chain is a common way to lose them. Be wary of tokens claiming to be a new L1 without an independent validator set or open-source node software, because some are just tokens on another chain with ambitious marketing. Also keep enough of the native coin in your wallet to pay gas, or you will not be able to move your tokens.