icloud drive documents and desktop

You can turn off the Desktop & Documents option (if you have it on) and put only those files that you want to be available to all devices in iCloud Drive. On your Mac, that folder is available via the Finder "Go" menu > iCloud Drive (you can also add that folder to the Finder sidebar for convenience).

The following has instructions on turning off Desktop & Documents: Add your Desktop and Documents files to iCloud Drive - Apple Support

It depends on whether or not you have the Optimize option turned on. See the following from Add your Desktop and Documents files to iCloud Drive - Apple Support

If you need more space on your device, iCloud Drive can help. On your Mac, go to Apple menu  > System Preferences > iCloud. Next to iCloud Drive, click Options and turn on Optimize Mac Storage. Then your Mac keeps all of your recent files on your computer, but keeps your older ones only in iCloud, ready for you to download when you need them again. If you want to free up more space on your Mac, follow these steps. On your iPhone, iPad, or iPod touch, you can search and browse files from all of your devices and download them only as you need them.