Disk Utility is the name of a utility created by Apple for performing disk-related tasks in Mac OS X. These tasks include:
the creation, conversion, compression and encryption of disk images from a wide range of formats read by Disk Utility to .dmg or, for CD/DVD images, .cdr;
mounting, unmounting, and ejecting disks (including both hard disks, removable media and disk images);
enabling or disabling journaling;
verifying a disk's integrity, and repairing it if the disk is damaged (this will work for both Mac compatible format partitions, and FAT32 partitions with Microsoft Windows installed);
verifying and repairing permissions;
disk erasing, formatting, partitioning and cloning;
secure deletion of free space or disk using a "zero out" data, a 7-pass DOD 5220-22 M standard, or a 35-pass Gutmann algorithm
adding or changing partition table between Apple Partition Table, GUID Partition Table, and master boot record (MBR);
creating, destroying, merging, and repairing RAID sets;
restoring volumes from Apple Software Restore (ASR) images;
burning disk images to CD or DVD in HFS+ format;
erasing CD-RWs and DVD-RWs;
checking the S.M.A.R.T status of a hard disk.
Disk Utility functions may also be accessed from the Mac OS X command line with the diskutil and hdiutil commands.
RazTK added Disk Utility as alternative to uDiscMounter
Danilo_Venom added Disk Utility as alternative to 4DDiG Partition Manager
Danilo_Venom added Disk Utility as alternative to 4DDiG Windows Boot Genius
Comments and Reviews
With the release of Mac OS X 10.11 ("El Capitan"), Apple redesigned the trusty Disk Utility to make it bright and colorful and, in the sad tradition of Apple's "simplification" of iWork, iPhoto and other apps, much less useful.
It has lost the ability to verify or repair file permissions. It can no longer resize disk partitions. There's nothing in the app at all about RAIDs. Apparently, some or all of these feature roll-backs are described as coming features, but that will be too late for people who want to do those things now.
Some enterprising folks have realized that if you can obtain a copy of your old Disk Utility and are not afraid of using the console and doing a bit of hex editing on the old copy, you can run the pre-nerfed version under 10.11.
Instructions: https://justus.berlin/2015/10/restore-old-disk-utility-in-os-x-el-capitan/
Disclaimer: running an old version of a tool as powerful as Disk Utility against a newer version of the operating system is not recommended or supported. By following the instructions in the article, you are definitely "coloring outside the lines." You have been warned.
Thanks
Reply written May 14, 2019