This feature is implemented at a low level, and works on the command line.<p>For example if you have a directory that is all stored in the cloud you can `cd` to it without any network delay, you can do `ls -lh` and see a list with real sizes without a delay (e.g., see that an ISO is 650 MB), and you can do `du -sh` and see that all the files are taking up zero space.<p>If you open a file in that directory, it will open, even from command line, then do `du -sh` and see that that file is now taking up space, while all the others in the directory are not.<p>You can right-click to pin files and directories to be stored locally, and right-click to send them back to the cloud so they don&#x27;t take up space.<p>This is actually very different than traditional network file systems like SMB, NFS, WebDAV, and SSHFS. With a normal network file system over the WAN you would have major latency problems trying to `cd` and `ls` the remote file system. Most of them also don&#x27;t have any ability to cache files locally when offline, or the ability to manually select which files are stored locally and which are remote. AFS does have some similar capabilities.