签名 (qiān míng) means 'to sign one's name' or 'signature' — it's the everyday word for signing your name on a document, a photo, or an autograph. It differs from 签字 (qiān zì), which is more formal and used in official contexts (e.g., signing a contract), and from 签 (qiān), a general verb for signing documents or agreements (e.g., 签合同).