Hello, I bought SSL certificate from my hosting webhostingpad.com

and they are telling me that I should decide should it work for domain with "www" or without.

Does it make any difference?

This is letter from hosting:

Your SSL will work in certain ways.

Your SSL is will be ordered for www.yourdomainname.com or yourdomainname.com


If you ask us to make certificate for www.yourdominname.com, your ssl will not work when you use yourdomainname.com and vice versa.

Please, help