title: Difference between git merge <branch> and git merge origin <branch>
body: <p>This is not a question on <code>git merge origin branch</code> vs <code>git merge origin/branch</code></p>
  
  <p><code>git merge &lt;branch&gt;</code> merges the  into the working branch. And so we need to specify the "source" of the branch. It can be a locally available <code>origin/&lt;branch&gt;</code> or the local working branch <code>heads/branch</code>.</p>
  
  <p>But what's the need for <code>origin</code>? Unlike <code>git pull</code> we don't need to specify which remote source to fetch the  from. A merge operation, to my understanding, is a local operation.</p>