What is a domain validated (DV) certificate?
A domain validated certificate is one in which the validated identifying information contained in the certificate is limited to the domain in which the Web site is located. If one of these certificates validates correctly, then the browser displays the padlock icon.
What is an organizationally validated (OV) certificate?
An organizationally validated certificate is one in which the validated identifying information includes the domain and information about he business entity that operates the Web site, such as its registered business name. Organizationally validated certificates differ from extended validation certificates in that they are not necessarily issued in compliance with the extended validation guidelines. Furthermore, the organizational identifying information they contain does not receive prominent display in the most popular browsers. If one of these certificates validates correctly, then the browser displays the padlock icon.
What is an Extended Validation (EV) certificate?
An extended validation (EV) certificate is a certificate issued in conformance with the extended validation guidelines. The organizational identifying information receives prominent display in some browsers.
Most browsers' user interfaces did not clearly differentiate between low-validation certificates and those that have undergone more rigorous vetting. Since any successful SSL connection causes the padlock icon to appear, users are not likely to be aware of whether the website owner has been validated or not. As a result, fraudsters (including phishing websites) have started to use SSL to add credibility to their websites.
By establishing stricter issuing criteria and requiring consistent application of those criteria, EV SSL certificates are intended to restore confidence among users that a website operator is a legally established business or organization with a verifiable identity.