Clear up Mac Storage

I think this will help to answer your questions.

The Other Category should not be altered, modified, move or deleted since it is part of the Mac’s operating system. Doing so would corrupt the OS and render the OS inoperative requiring a Wipe and Re-Installation.

The Other category is a potpourri of files which include:

• System temporary files

• macOS system folders

• Archives and disk images (.zip, .iso, etc. - often found in the Downloads folder)

• Personal user data

• Files from the user’s library (Application Support, iCloud files, screensavers, etc.)

• Cache files

• Fonts, plugins, extensions

• Other files that are not recognized by a Spotlight search

• Media files that cannot be classified by Spotlight as a media file because they are located inside of a package

They can be located anywhere on your hard drive. The files that you have control over are located in the Documents, Downloads, Pictures, Music and Movies folders.

Also, if your OS becomes too full your computer will stop functioning. This is a good time to seriously consider adding an external drive for storage. Then you can move files onto it and then delete them from your HD to clear needed space. Easy to do and problem solved.

We cannot trust the Storage report as to where the usage really is, 4 suggestions, especially what “Other” is…

And apparently Apple has a new way of hiding files & more than a few find out the only way is to Backup, then Erase the Drive!?

Have you emptied the trash lately?

Terminal code to clean DocumentRevisionsfolder…

https://apple.stackexchange.com/questions/313102/what-will-occur-if-the-documentrevisions-v100-folder-is-deleted

macos - What will occur if the .DocumentRevisions-V100 folder is deleted? - Ask Different (stackexchange.com)

https://discussions.apple.com/thread/253231342?answerId=256043117022#256043117022

System Memory OS 10.12.6 Sierra - Apple Community

Look for iOS backups…

/Users/YourUserName/Library/Application Support/MobileSync/Backup

OmniDiskSweeper shows you the files on your drive, largest to smallest, and lets you quickly Trash or open them.

https://www.omnigroup.com/more/

Purging local backups

Please note that although this doesn't affect your remote backup from Time Machine, this will get rid of the redundancy (at least until the next Time Machine backup) that a local backup disk will provide. If you need such redundancy or are worried about the recovery of your data then you would be best served to let macOS determine when to purge these files.

Start Terminal from spotlight.

At the terminal type tmutil listlocalsnapshotdates. 

Hit enter.

Here, you'll now see a list of all of the locally stored Time Machine backup snapshots stored on your disk.

Next you can remove the snapshots based on their date. I prefer to delete them one at at time. Once my "System" disk usage is at an acceptable level, I stop deleting but you can delete all of them if you want to reclaim all of the disk space.

Back at the terminal, type tmutil deletelocalsnapshots YYYY-MM-DD-HHMMSS , where will be one of the dates from your backup. This will be in the form of xxx-yy-zz-abcdef. Try to start with the oldest snapshot.

Hit enter.

Repeat for as many snapshot dates as required

http://www.thagomizer.com/blog/2018/03/27/cleaning-up-time-machine-local-snapshots.html

tmutil deletelocalsnapshots /  # deletes all the snapshots