Can I have multiple subdomains working with one WordPress installation?

Hi. I’m trying to setup my website in WordPress and I need some help.

• I have one main WordPress installation in the www root folder: example.com
• From the admin I can create Pages. I created one called “Motion” and the url looks like this: example.com/motion
• Also, I registered a subdomain in my server called: motion.example.com and they told me that the content should be placed in a separated folder called “motion” located inside my www folder

As far as I know, WordPress have the page structure inside the database, not in physical folders, so I don’t understand how I can make my subdomain to work. I would love to have my url looking like this: motion.example.com/demo/sample-project but with the admin I only can make it look like example.com/motion/demo/sample-project

Thanks in advance for any help