In cryptography, a public key certificate (also known as a digital certificate or identity certificate) is an electronic document that uses a digital signature to bind a public key with an identity — information such as the name of a person or an organization, their address, and so forth. Digital Certificates provide a means of proving your identity in electronic transactions; much like a driver license or a passport does in face-to-face interactions. With a Digital Certificate, you can assure friends, business associates and online services that the electronic information they receive from you are authentic.
The most widely accepted format for Digital Certificates is defined by the CCITT X.509 international standard; thus, certificates can be read or written by any application complying with X.509. Further refinements are found in the PKCS standards and the PEM standard.
What are digital signatures?
A digital signature functions for electronic documents in a way that is similar to what handwritten signature does for printed documents. The signature is a piece of data that cannot be forged and thereby, asserts that a specific person wrote or otherwise agreed to the document to which the signature is attached.
The server certificates enable Web servers to operate in a secure mode. A Server Certificate unambiguously identifies and authenticates your server and encrypts any information passed between the server and a Web browser.
The developer certificates are used in conjunction with software validation Technology and provide customers with the information and assurance they need while downloading software from the Internet.
The classification of certificates is not specified in PKI standards and vendors may choose to use different classes or no classes at all.
Personal Digital Certificates
The personal digital certificates are used by individuals when they exchange messages with other users or online services.