OS X El Capitan brought numerous changes to OS X and among them was a massive overhaul of the popular Disk Utility. The new version is pretty and pretty useless. Jonny Evans:
Gone is the box-like Disk Utility of yesterday to be replaced by a more colorful edition providing at-a-glance information of how you use your disk.
This means you can see just how much of your Mac is consumed by Apps (blue), Photos (red), Audio (orange), Movies (green), and everything else, aka “Other” (yellow). You can also see how much (or, in my case, how little) space is free (white). This is pretty much the same view as you’ll find in About this Mac under the Storage pane.
Disk Utility launches with this view and offers five choices to reach its remaining tools in its top bar: First Aid, Partition, Erase, Unmount and Info.
Verify disk, RAID, and burn CD/DVD.