Domain validation = The certificate ensures that your domain name is protected and secure. The person or organization behind the domain is not verified.

Domain validation (wildcard) = Same as domain validation, but with a wildcard certificate, you can also protect one or more subdomains, such as www.domain.com and in addition blog.domain.com or shop.domain.com.

Extended validation = The certificate ensures that the domain name used by the customer is protected and secure, and that the domain owner exists and is verified. This certificate is generally recommended for e-commerce.