Domain Validation (DV) is a basic type of validation where the certificate authority validates domain authentication/ownership. DV certificate is an ideal for blog, single website.
Organization Validation (OV) is requires business authentication and is one step upper level certificate compare to DV certificate. It follows business and domain authentication to show customers that they are dealing with the secured website.
Extended Validation (EV) SSL carries the highest verification level than DV and OV certificates. It shows a company name when a customer clicks on a padlock. The certificate authority checks legal, operational, and physical business proofs to authenticate the business.