“Other” storage on Mac is files that don’t easily fall into the defined categories of “Audio" “Movies” “Photos” “Apps” and “Backups”. The types of files found in “Other" would include: • macOS system files, • temporary files, • app plugins and extensions, • browser and Mail caches, • documents like .pdf, .psd, .doc, • disk images and archives like .dmg, .tar, .zip
You cannot directly manage the contents of this category. That is done by macOS, and the category varies in size depending on the current state of your Mac.
What you can do...
• Empty the Trash in the Dock.
• Empty the trash in the Photos app.
• Delete unused and unneeded installers from your downloads folder and desktop.
• Transfer files that you don’t use daily to an external drive. Files that take up the most room are movies, images and music.
• Force Time Machine to delete local snapshots:
About Time Machine local snapshots - Apple Support
This from Apple on the subject of storage management:
Free up storage space on your Mac - Apple Support
And this for a better, more thorough explanation:
What is “Other” and what can I do about it? - Apple Community (Kappy)