What does the tool download?

I am still not 100% sure what the tool decides to download, does it matter which machine I run the updater on? (As in if the machine I run the download tool on has all current updates, will this effect what is downloaded?
I largely use this amazing tool to update machines I have reset and bring back up to modern updates, I have noticed that when I run the tool usually it does not seem to install the 1511 update and usually this is done by Windows updates after I run the updater.exe
Many thanks
I largely use this amazing tool to update machines I have reset and bring back up to modern updates, I have noticed that when I run the tool usually it does not seem to install the 1511 update and usually this is done by Windows updates after I run the updater.exe
Many thanks