What do the Software Update options do?
Apple documents the difference between an update and an upgrade as follows:
- https://support.apple.com/kb/HT201564
Updates within each named OS include security, performance and sometimes new features. They are focused on the first two.
Upgrade is from Lion to Mountain Lion or Mavericks to Yosemite. These are primarily about large feature introductions and major changes.
Sometimes a big change will arrive as an update, but in general you have to purchase (even if it's a free redemption) upgrades whereas updates can be automated with the software update app and or the software update portion of the Mac App Store.
Historically, the two were separate, but it's a bit more confusing now since everything the normal end user sees is in the App Store app.
You can see what updates are pending by running the command softwareupdate -l in terminal and it will only list system updates.
You're correct.
I have "Install App updates" and "Install system data files and security updates" checked in System Preferences and "Install OS X updates" deselected, and exactly what you describe is what I observe.
OS X Updates are user-facing updates that directly affect the user, regardless of whether the user actually uses the respective app (e.g. RAW updates).
The system/security updates are the Security Updates and File Quarantine (XProtect) definitions.
In the last 30 days according to my App Store Updates tab, the following was not auto-installed for me with "Install OS X updates" disabled:
- Command Line Tools (OS X 10.10) 6.3
- Digital Camera RAW Compatibility Update 6.04
- Remote Desktop Client Update 3.8.4
OS X 10.11.0 would be considered a separate app on the App Store, so it wouldn't be automatically updated from a version prior to 10.11.0 regardless of the settings.