title: Git checkout first time versus subsequent uses
body: <p>So, i am at my master branch working.</p>
  
  <p>I issue :</p>
  
  <pre><code>git checkout -b branch1
  </code></pre>
  
  <p>This will create a new branch named branch1 and will make it identical to my current branch master.</p>
  
  <p>Git does this "mirroring" only the first time that i run it?</p>
  
  <p>Every subsequent call to git checkout will just fetch the data for the branch i checkout?</p>