title: What exactly does Source on Save mean or do?
body: <p>Despite numerous searches, I can't seem to find a clear explanation as to what "Source on Save" means in RStudio.</p>
  
  <p>I have tried <code>?source</code> and the explanation there isn't clear, either.</p>
  
  <p>As far as I can tell, it seems to run the script when I hit <code>Save</code>, but I don't understand the relevance/significance of it.</p>
  
  <p><strong>In simple terms, what exactly does Source on Save do and why would/should I use it?</strong></p>