How did you find that link?
Download the software catalog:
http://swscan.apple.com/content/cat...n-lion-snowleopard-leopard.merged-1.sucatalog
Open it in a text editor and just scroll through it. A full OS installer will have "InstallAssistantAuto" and "InstallESD" in the names. The updates seem to have "macOSUpd" in the name. There's a "post date" below them in the plist that shows when it was uploaded.
Hope that helps. I'm not advising you to try installing this way. But this is what I do usually because I do not like automated tools and I'd rather do things 100% myself.
Edit: The updates aren't full installers. You can't install a fresh copy of the OS from them, only update over existing one.