Base runs applications using the Ethereum Virtual Machine, allowing familiar Ethereum wallets and development tools to connect to its network. Mainnet has chain ID 8453 and uses ETH for fees; its Sepolia test network has a separate identifier. This distinction matters operationally: an Ethereum address can receive assets on Base while its Ethereum-mainnet balance remains unchanged. Applications and exchanges must identify the chain as well as the asset, and a token symbol alone does not establish the correct destination or contract.

Base documentation separates a sequencer preconfirmation, inclusion in an L2 block, posting of the transaction batch to Ethereum, and finality of the corresponding Ethereum data. A quick wallet receipt is useful for interacting with an application, but it is earlier in that sequence than Ethereum finality. A merchant or exchange deciding when to credit a payment is choosing which guarantee to rely on. The relevant evidence is the transaction's settlement stage, not merely that an explorer has displayed a successful execution result.

The canonical path from Base to Ethereum includes a challenge window for a proposed output used to establish the withdrawal. Base's documentation describes a seven-day process; this does not mean ordinary transfers and swaps within Base wait seven days. If a proposal is successfully challenged, withdrawals relying on that proposal must be proven against a valid alternative. A different bridge can offer a faster experience by supplying destination liquidity, but that introduces a separate service and settlement path. Its speed should not be confused with completion of the canonical withdrawal.