Client Questions about 'Flat file'

Hello!

I have a customer who wants to self-host and they need to know if the exported site will be flat file or have a database. (I’m a no coder so I’m not entirely sure what this means.)

This will be a basic site for a physical store. No blog or other features, just some HTML, CSS, JS, photos, and a contact form.

Can someone confirm if this is flat-file?

It’s a type of CMS.
With static there will only be the HTML CSS and Javascript.

Thank you! Really appreciate the confirmation!