You use SSL certificates to set up your website with the HTTPS protocol, which encrypts all data between a user’s browser and your web server. A standard SSL certificate is perfect when you want to secure your website and protect your visitors personal information. But what if you use subdomains on your site for different purposes? How do you secure all the subdomains on your site?
A wildcard SSL certificate does precisely that: it is an SSL certificate that not only secures your primary domain but all the subdomains you have for that specific domain. Rather than purchase a certificate for every subdomain, you can purchase a single wildcard certificate and cover all your subdomains.
If you used the domains yourdomain.com, blog.yourdomain.com, support.yourdomain.com, and email.yourdomain.com, you can secure all of them at the same time by requesting a wildcard SSL certificate for *.yourdomain.com.
If you used the domains www.yourdomain.com, blog.www.yourdomain.com, and recipes.www.yourdomain.com, you can secure all of them at the same time by requesting a wildcard SSL certificate for *.www.yourdomain.com.