title: Github Desktop: "Update from <branch>" button
body: <p>In this picture below from the Github(c) Desktop App there ist this button "Update from master" (in this case). I was wondering if anyone had the insight what exact <strong>git</strong> function it triggers. Primarily I'm interested if <em>merge</em> or <em>rebase</em> is used. (I could not find any sort of log console).</p>
  
  <p><a href="https://i.stack.imgur.com/1Ew7p.png"><img src="https://i.stack.imgur.com/1Ew7p.png" alt="enter image description here"></a></p>