[SixDouble5321]

Not to diminish package managers, I don't think they are having to be quite as clever as Windows update, at least historically. I could be wrong, but I think they are more like dependency tree managers that also download and execute new installers.

[forgotpwd16]

No, they aren't clever. They're practical. There's no such thing as execution here. Packages are archives containing the entire files not differences. The manager downloads it, unpacks it, and adds/removes/replaces the package's files in the system.

[GrayShade]

They can also execute post-install or post-update scripts. And indeed, Linux package managers aren't as fancy as Windows Update is, but that fanciness isn't something I miss.

My distro's package manager probably breaks my system if it loses power during an update. Even so, it's been one of the more reliable and pleasant to use programs I've encountered.