To sign, that is, to write one's name, especially to express agreement, recognition, responsibility or obligation. There are more interpretations of signature, such as digital signature, artistic signature and so on. Or a star's meaningful signature, also called signature. Signature is a kind of signature, because the signature is used the most, so the signature is often corrupted into a signature. Traditionally, signature is not synonymous with signature. The signature should be readable, but the signature is unnecessary. People have certain requirements for signature, and the signature represents the consent, which has legal effect and gives the document authenticity in law.

In real life, some methods (such as handwriting, fingerprints, etc. ) has been used as proof of the identity of the signer. This is because: the signature is credible; Cannot be forged; Not reusable; Undeniable; The signed document is irrevocable. In the coming digital life, electronic documents will gradually replace paper documents as the main body of information exchange. The way to prove that the electronic document is made by the author is to make an electronic signature on the electronic document by simulating the ordinary handwritten signature. The author can identify himself by digital signature, and the reader can verify the identity of the author by digital signature.