title: git - move branch "tag" to other commit?
body: <p>Since a branch is more or less only a tag, that moves automatically to the new commit, I wonder if I can modify this "tag".</p>
  
  <p>Example:</p>
  
  <pre><code>             master  
  A -- B -- C -- D
  </code></pre>
  
  <p><code>git checkout master</code> would be the same as <code>git checkout D</code></p>
  
  <p>Can I change master to point to commit B?</p>
  
  <pre><code>   master
  A -- B -- C -- D
  </code></pre>
  
  <p><code>git checkout master</code> would now be the same as <code>git checkout B</code></p>
  
  <p><strong>Use Case</strong></p>
  
  <p>Imagine someone has pushed one single commit to the online repository. When I do <code>git fetch</code>, I get this commit local, but my master branch still points to the commit before, while origin/master points to the new commit. I just want to move the local master branch to the same commit as origin/master points to.</p>
  
  <p>So, I wouldn't have to merge.</p>
  
  <p>Thanks for your help</p>