Apple computers running the latest versions of the OS X operating systems, such as Mavericks (10.9) or Yosemite (10.10) will be notified when system updates and software updates are available in the App store, as shown below.
If you click on the “Later” option, you’ll be given an option to be reminded later, or to have updates installed automatically. It’s okay to choose the ‘remind me later’ options, but it’s not a good idea to choose automatic installation of update because occasionally there are updates that will cause problems for your computer. Below is an example where a software supplier is telling users not to install the available update since it’s known to have a bug. Click the image for a larger view.
If automatic updates were turned on, this update would be installed and the software would not work properly.
A day later, the app developer released a new working version of their software. Click the image for a larger view.
Those without the automatic updates feature turned on were able to continue doing their work, skipping the defective update, and then getting the correct update when it was released.