What the “Other” Storage Space is in Mac OS X?

Solution 1:

Essentially it’s anything that OS X does not allocate to the listed specified storage types of applications, backups, audio, movies, backups, and photos. That means a very broad list of items will be considered as Other, including things like the following:

  • Documents and file types, including PDF, doc, PSD, etc
  • Archives and disk images, including zips, dmg, iso, etc
  • Various types of personal and user data
  • Anything in the system folders of OS X, ranging from temporary files, swap, voices, etc
  • User library items like Application Support, iCloud files, screen savers, etc
  • User caches and system caches, including things like browser caches and locally stored message media files
  • Fonts, app accessories, application plugins, and app extensions
  • Various file and file types not recognized by Spotlight, for example a virtual machine hard drive, Windows Boot Camp partitions, etc

As you can see, this is not unnecessary junk or clutter. Basically, anything that is not one of the media types that the Storage tab specifies will be shown as “Other”.

Source: OS X Daily: What the “Other” Storage Space is in Mac OS X & How to Clear It Up