Files stored in iCloud have a download icon (a cloud with an arrow pointing down). When your Mac is low on storage, only recently opened files are stored on your Mac. Desktop and Documents: iCloud stores all of the files located in these two folders.When storing files on iCloud, you can choose from one of three options: Storing your content on iCloud, Apple's cloud storage service, helps you save space on your computer while still having easy access to your files.