What are subdomains?
A subdomain is a domain that is created by using your main domain name and a prefix name. Many websites use subdomains as a way to create separate areas or functions of the website. For example, domain.com might use the subdomain checkout.domain.com to handle customer check outs, and info.domain.com for customer information, etc. If your website uses subdomains and you wish to secure several different subdomains, we recommend a Wildcard SSL Certificate, which allows you to secure unlimited subdomains with a single certificate.