Maybe I was not too clear in asking the question. You are correct that I have only one physical drive and both the virtual Z drive and the C drive show the same available space. I understand this. However, my question is .... why should dragging a one Gig file from the C drive to the Z drive take my total available drive space from 9 gigs to 8 gigs instantly???
The question should be apparent from what is asked above the line and perhaps what I have to say further will confuse the issue. I understand the concept of cloud storage to share across devices. Things remain on the compter, or computers, and the updates are synced and there are several copies of the same files out there. BUT, what about if I want to conserve space on my drive because I have only 9 gigs and want to use the extra few free gigs offered by Dropbox and others? In other words, I want just the link to the files stored on my computer, the complete files stored only on the cloud and to access those files only when I need them. Of course I realize I have to essentially download them each time I want to use them, but I am basically just using the cloud to backup files in case my computer crashes so I have critical files.