Domain Validation (DV)
DV or a Domain Validated Certificate is a certificate that only requires you to verify that you are the owner of your domain. This occurs by receiving an email that is sent to the WHOIS information or email addresses belonging to that domain to verify that you own the rights to use the domain. This happens immediately for fast issuance, but sometimes lacks trust because almost anyone can get a DV certificate issued. 

Organizational Validation (OV)
For Organization Validated (OV) Certificates, the issuing Certificate Authority (CA) validates your organization information to make sure you are an actual organization. They verify the Organization Name, Physical Address, and Phone Number. This data must match with the WHOIS information and also a public Government Information website or an approved Third-Party Website before being issued. OV certificates add more trust to a consumer because they are assured that they are doing business with a real corporate entity. 

Extended Validation (EV)
EV or Extended Validation Certificates (also known as "Green Bar" Certificates) are recognized and known as the most highly trusted type of SSL certificate. During the EV verification process, the issuing vendor or CA totally verifies that you are a legitimate business and in good standing above and beyond an OV verification process. Once this process is successfully completed and your EV SSL is issued, all of the browser indicators will be activated on your site to let your customers know that you can be trusted. The most important indicator that becomes active is the "Green Bar" in a user's web browser. Research shows that people are aware of the green bar and view it as being trustworthy. EV certificates are the only certificates where potential ROI exists…because more trust means more confidence; which could mean they are more likely to buy from you.