MacOS Disk Utility is a built-in application on MacOS that helps users manage their storage devices. It allows you to format, partition, and repair disks, ensuring they function properly. You can also create disk images and manage external drives easily. The tool provides a user-friendly interface for checking the health of your disks and performing maintenance tasks. With features like First Aid, users can troubleshoot and fix common disk issues, making it an essential utility for maintaining the performance and reliability of your Mac system.