You have Mac system and suppose you have to take care of all its functions. Undoubtedly, you are liable for taking care of them at your business, thus, you might need a toolkit of applications which will help you in sorting out your troubles when Mac is not working properly or may be suffering from any issue. It might be possible that its hard drive needs rebuilding or recovery, memory needs testing. It might be possible that you want to undelete some files, may need to access deeper system maintenance or simply want to clean out debris from old apps of your mac system. Keeping all the above said points in mind, developers of Mac system has introduced a functionality called Disk Utility which comes with Mac OS itself. You need not to have it externally. Here, have a brief look on free mac disk utility.