"Knowing when signing a contract" is a common legal term, which means that when an individual or organization signs a document or contract, it confirms and understands the contents of the document or contract and voluntarily accepts its terms and obligations. Signing means "expressing approval of the signed content", and signing is an act of meaning, indicating agreement, approval, responsibility or obligation. The legal effect of a signature is to clarify the identity, confirm the contents of the agreement, voluntarily be bound by the law and bear legal responsibilities.