I've been using Windows my entire life. and I just bought a new (to me) MacBook Pro. I'm trying to get everything set up and transferred onto the new machine. I'm stuck on one feature. I've read articles on 5-6 various websites now, trying to comprehend what exactly is going on with the new iCloud features. Some reviewers advised to turn it off either partially, or completely. First... System Preferences > iCloud > iCloud Drive > Desktop and Documents Folders Most of the reviews were from the initial release of Sierra. What is the general consensus now? Leave it on or turn it off? If this is toggled on, are files that I save stored completely in the cloud completely? Is it also saved locally? Second... At the bottom of the window, there is a toggle for "Optimize Mac Storage." If this is on, are all my files stored on the SSD until free space is low? What is the threshold where it considers the drive low on free space? If it does become low, iCloud will delete local files and keep them stored in iCloud? Whatever files it thinks aren't important to me? If I toggle optimize storage off, it stores everything in Desktop/Documents in iCloud and not locally at all? Am I understanding this correctly? Third... About This Mac > Storage > Manage Some of this stuff seems redundant? There's another section dealing with Photo and Video optimization? Just leave this alone? Lastly... Is the entire Pictures folder synced with iCloud, or just the Photos Library subfolder? My Lightroom catalog is in the Pictures folder by default, and having that uploaded to iCloud would wreak havoc. With files on my Windows machines, I would keep a local copy, a local backup, and an online backup through CrashPlan. I'd like to do it this was on the Mac too, but if files are only stored in iCloud, then they wouldn't be accessible to CrashPlan or TimeMachine backups. I also wouldn't be able to access them while I'm offline. I'm in love with my new MacBook, and eventually plan on buying an iMac when they are refreshed. It would be nice to have my desktop and documents synced across machines, but not if they are 100% stored in the cloud. Hopefully someone can clear this up for me, and correct me where I'm wrong. I may be completely misinterpreting the way this works.