A smart contract wallet is an onchain account controlled by programmable code instead of a single private key, built on a design pattern called account abstraction. That code can enforce spending limits, require multiple approvers, or let a trusted guardian restore access if a device gets lost. The main advantage over a traditional wallet is resilience: losing one key no longer means losing everything, and the account can be programmed to handle gas payments, permissions, and recovery on its own terms. ERC-4337 is currently the dominant standard making this possible on Ethereum and its compatible networks.