Windows Update and AntiVirus and Firewall, what r their difference

what are their difference?

Can I live without installing AntiVirus or Firewall but only updating Windows security packs??

What is the thing that AV or Firewall can help while Windows update / security packs would not??

If I disable AdBlock and so there could be lots of popups in some websites. A lot of time you will accidentally clicking on some of the popups before you close it. Could it infect virus in that case

Let's block ads! (Why?)

Windows Update and AntiVirus and Firewall, what r their difference