According to Wikipedia, “A signatureis a handwritten (and often stylized) depiction of someone's name, nickname, or even a simple "X" or other mark that a person writes on documents as a proof of identity and intent. The writer of a signature is a signatory or signer. Similar to a handwritten signature, a signature work describes the work as readily identifying its creator. A signature may be confused with an autograph, which is chiefly an artistic signature. This can lead to confusion when people have both an autograph and signature and as such some people in the public eye keep their signatures private whilst fully publishing their autograph."