0x1fad948c?0x1fad948c is the function selector for handleOps((address,uint256,bytes,bytes,uint256,uint256,uint256,uint256,uint256,bytes,bytes)[],address). Executes ERC-4337 user operations.
When a transaction's data begins with 0x1fad948c, it is calling handleOps. The selector is the first four bytes of the keccak-256 hash of the signature handleOps((address,uint256,bytes,bytes,uint256,uint256,uint256,uint256,uint256,bytes,bytes)[],address), which is how wallets and explorers work out which function a payload is for.