Today there are three types of certificates that offer 3 levels of user trust for SSL/TLS negotiations:
Domain Validated certificates (DV), Organization Validated certificate (OV) and Extended Validation certificates (EV).

Domain Validated Certificate
This type of certificate validates that the domain is registered and someone with admin rights is aware of and approves the certificate request. The validation can take from a few minutes to a few hours. The Domain Validated SSL certificate is the most common SSL certificate type because it’s fast to purchase. This validation type is sufficient for the majority of businesses and cheaper compared to Company or Extended validations.
If the certificate is valid and signed by a trusted authority, the browsers indicate a successfully secured HTTPS connection.

Organization Validated Certificate
Organizational certificates are Trusted and they are authenticated by real agents against business registry databases. Additional business documents may be required and the business may be contacted during validation to prove the right of use. OV certificates therefore contain legitimate business information. This is the standard type of certificate required on a commercial or public facing website.

Extended Validation Certificate
The Extended Validation certificate requires an extended validation of the business. It validates domain ownership and organization information, plus the legal existence of the organization. It also validates that the organization is aware of the SSL certificate request and approves it. The validation requires documentation to certify the company identity plus a set of additional steps and checks. The order can take from a few days to a few weeks, due to the extended validation process. The Extended Validation SSL Certificates are generally identified with a green address bar in the browser containing the company name.