Web addresses

www.website.com is technically a different web address than website.com

Though most people will register both. You can have each go to a different place. It is common for some sites to flat out not support www. Other sites can glitch out if it requires HTTPS and you type HTTP when entered with WWW.

Sounds like a generic home work question. So I'm not going to give you the perfect answer. Research can be started here - you have to figure out in what section of this table the WWW section refers to.

http://en.wikipedia.org/wiki/List_of_DNS_record_types

Good luck!

and the other doesn't.

Here's your sign...