While the storage summary panel provides a helpful overview of where the disk usage and capacity is consumed on any Mac, it is not an actionable screen that allows users to clean up their drives or file system. In the above screen shot example, the “Photos” section is taking up the vast majority of disk space, which is fairly common for users who take a lot of photos and transfer them to the Mac from an iPhone or other camera.

(Free space) – the last item in the graph that is transparent, this is the freely available space shown in relation to used capacity.

Other – every other document and file type on the Mac, including archives, zip files, docs, txt, pdf, dmg and other images like iso, saved messages, quite literally everything else, similar to “Other” in iOS.

Backups – all locally stored backup files from Time Machine or iPhone (this is often zero KB if you turned the feature off).

Apps – all applications and executable files, including the /Applications directory and any other.

Photos – all picture documents stored locally, including user imported photos from an iPhone or Camera, screen shots, or digitally created image files from Photoshop and Pixelmator.

Movies – all movie files, whether user created from iMovie or downloaded from iTunes or elsewhere on the web.

Audio – all music and audio files stored on the Mac, including the iTunes Song and Music libraries.

The usage overview will show the freely available disk space like the Finder Status Bar, but also show the total drive storage capacity, and six general categories of data in an easy to scan graph: Making Sense of the Mac OS X Storage Summary If this screen looks familiar, it may be because the usage overview for Mac OS X is a lot like looking at the usage summary in iTunes for a connected iOS device, which also breaks down details on space usage. This will also quickly show what type of hard drive is included in the Mac, whether it’s a traditional hard drive, a “Flash Storage” drive (SSD), or a Fusion Drive. The storage overview looks like this, showing the disk space used on a Mac and the disk space available:

From the “Storage” tab, see the disk storage overview and capacity summary.

At the general ‘About This Mac window’, click on the “Storage” tab (or if you’re running an earlier Mac OS X version, click on “More Info” button).

From anywhere in Mac OS, choose the  Apple menu item and select “About This Mac”.

If you want to check a Macs disk space and disk usage, this is one of the simplest ways to do so:

This tutorial will detail how you can view a disk usage and storage summary on a Mac.

How to clear space on disc mac