An electronic signature, or e-signature, is data that is logically associated with other data and which is used by the signatory to sign the associated data. This type of signature has the same legal standing as a handwritten signature as long as it adheres to the requirements of the specific regulation under which it was created (e.g., eIDAS in the European Union, NIST-DSS in the USA or ZertES in Switzerland).
Electronic signatures are a legal concept distinct from digital signatures, a cryptographic mechanism often used to implement electronic signatures. While an electronic signature can be as simple as a name entered in an electronic document, digital signatures are increasingly used in e-commerce and in regulatory filings to implement electronic signatures in a cryptographically protected way. Standardization agencies like NIST or ETSI provide standards for their implementation (e.g., NIST-DSS, XAdES or PAdES). The concept itself is not new, with common law jurisdictions having recognized telegraph signatures as far back as the mid-19th century and faxed signatures since the 1980s.