An electronic document, signed with a digital signature, that attests to the ownership of something; especially a certificate signed by a certification authority who attests to the ownership of a public key by an individual or an organization. X.509 is an international standard that defines a framework for authentication services and specifies formats for public key certificates.
Electronic document, delivered by a certificate authority, that guarantees the authenticity of the public keys contained in a directory. A digital certificate specifies the holder of the public key, the public key itself and the expiration date of the key.
A digital certificate is an electronic ID card that proves the sender's identity. A digital certificate is issued by a certificate authority.