How to Use a Combo Update to Install Mac OS X Updates
Most Mac users update their system software through the Mac App Store, which is quick, easy, and efficient. There is absolutely nothing wrong with updating Mac OS X through the App Store, and that approach is best suited for the majority of users, but many advanced Mac users and systems administrators rely on what are called Combo Updaters to update Mac OS to the latest versions available. Additionally, combo updates can be helpful for troubleshooting a failed Mac OS X update, and running through one can often remedy a broken or borked update attempt.