title: What Does a Standard "Installation" actually do?
body: <p>I'm just a hobbyist programmer more or less and have grown up coding-wise in the .NET ClickOnce world.</p>
  
  <p>When one "installs" a program, what actually happens?!</p>
  
  <p>Also: Some little apps/tools just run from the exe. Why do most programs need a fancy installation process? What are the advantages, disadvantages, pros &amp; cons? Is installation usually necessary or more like standard practice?</p>
  
  <p>Apologies for the extra questions. I'm just hoping for a plain-English more-or-less layman's explanation of the key factors.</p>