A document (based on the UIDocument class in iOS or the NSDocument class in OS X) is an assemblage of related data that can be written to disk as a single file or as a file package. Adopting iCloud document storage makes your app’s documents available on all of a user’s devices. Both Macs and iOS devices use iCloud to store app data and important files.
Once you've done that, select Summary and then choose This How to put iCloud Drive on a diet. Select 'Backup' to review older backups and delete those no longer needed. Or you can simply right-click on the selected files, and choose 'Move to Trash' option from the list menu. Select the files you want to get rid of them and drag them into the trash can located at the bottom of the screen.
