iCloud

No. iCloud is more or less automated syncing storage, not a hard drive somewhere. If you want that kind of storage look to other cloud providers such as Google Drive, Dropbox, Box, etc.

You can probably control some of that by simply being selective as to which folders you have used with iCloud and which files you keep in them. I don't have a single file in my "Documents" folder because I simply never used a computer that way and keep all my documents in my own folder structure. You can also turn off iCloud Drive on your Mac and use a web browser to interface with iCloud.com to control exactly what is where.

Rationale behind iCloud storage - Jan 2016 - https://discussions.apple.com/message/29713224#29713224 - "iCloud is not archival storage. It is not designed to be place to store your content off-device. That's what Dropbox or LiveDrive does better.

It is designed to easily sync your content between multiple devices. Photos, contacts, calendars, music and so on is accessible from whatever device you want in near real time. This is possible because iCloud is the place content is sent to and received from. An intermediate step. Not a destination, but a step along the way."