Disk Utility

Disk Utility is a system utility for performing disk and disk volume-related tasks on macOS.
Features include:

Create, convert, backup, compress, and encrypt logical volume images from a wide range of formats to .dmg or, for CD/DVD images,.cdr
Mount, unmount and eject disk volumes
Enable or disable journaling
Verify a disk's integrity, and repair it if damaged
Erase, format, partition, and clone disks
Securely delete free space or disk using a "zero out" data, a 7-pass DOD 5220-22 M standard, or a 35-pass Gutmann algorithm
Add or change partition table between Apple Partition Map, GUID Partition Table, and master boot record
Restore volumes from Apple Software Restore images
Check the S.M.A.R.T. status of a hard disk

Disk Utility functions may also be accessed via the command line with commands diskutil and hdiutil. The commands also can create and manage RAM disk images.

WWW Official Site

History

In the classic Mac OS, similar functionality to the verification features of Disk Utility could be found in the Disk First Aid application. Another application called Drive Setup was used for drive formatting and partitioning and the application Disk Copy was used for working with disk images.
Before Mac OS X Panther, the functionality of Disk Utility was spread across two applications: Disk Copy and Disk Utility. Disk Copy was used for creating and mounting disk image files whereas Disk Utility was used for formatting, partitioning, verifying, and repairing file structures. The ability to "zero" all data on a disk was not added until Mac OS X [10.2|Mac OS X 10.2.3]. Further changes introduced in Mac OS X Tiger, specifically version 10.4.3, allowed Disk Utility to be used to verify the file structure of the current boot drive. Mac OS X Leopard added the ability to create, resize, and delete disk partitions without erasing them, a feature known as live partitioning. In OS X El Capitan, Disk Utility has a different user interface and lost the abilities to repair permissions due to obsolescence, create and manage disks formatted as RAID, burn discs, and multi-pass format internal solid-state drives and encrypted external drives.