Disk First Aid is the name of a disk repair utility that was included or available for download with Mac OS 9.x or earlier. Disk First Aid was able to analyze and repair basic hard drive problems.
Disk First Aid was not a full-featured disk repair tool. It concentrated on just the basics: repairing catalogs, extends, and volume bit maps. Disk First Aid was truly a first line of defense, able to correct minor problems. When Disk First Aid was unable to make a repair, which was quite common, third-party disk utility tools could often do the trick.
With the advent of OS X, Apple vastly improved on the supplied ability to repair a hard drive, and folded the functionality of Disk First Aid into the Disk Utility application. Disk Utility is an all-around workhorse, providing nearly all the tools and features most users need to work with hard drives or disk images.
