A certificate secures the connectionbetween a browser and a web server using HTTPS. With a certificate on your website users will see the lock and HTTPS in the address.
(DV) Certificates verify your ownership of the domain, while Organization Validated (OV) Certificates prove that you own the domain and that your organization is legitimate. This is reassuring to your site visitors, as a fraudulent website would never pass these checks. The Extended Validation (EV) SSL offers the highest level of assurance to your customers – EV SSL applicants must pass an extensive vetting process.
Extended Validation (EV) certificates are single-domain SSL (Secure Sockets Layer) certificates that offer the highest degree of authentication and SSL protection. To ensure this, they require more evaluation and documentation checks for applicant websites than other certificate types. EV SSL certificates include a manual validation step to confirm. EV Certificate Prices range from $300 to $900 CDN and $250 to install on the server.

A Standard SSL Certificate is a single-domain SSL (Secure Sockets Layer) certificate and it establishes a secure connection between a browser and a server to encrypt communication.