title: How to understand git log --graph
body: <p>I am quite confused with the output of graphic git log.</p>
  
  <p>I do understand that each <code>*</code> means a commit, whether it is a diverge, common or merge commit.
  I do understand that pipes means branch.</p>
  
  <p>Let's look at a simple graph log:</p>
  
  <p><img src="https://i.stack.imgur.com/brAtv.png" alt="enter image description here"></p>
  
  <p>First of all, which branch does the red pipe (the most left-handed one) represent for? I don't think it is the current branch that I am on, because after I checkout to other branch, the graph looks the same. Furthermore, it doesn't represent master branch neither. </p>
  
  <p>Second of all, if the most left-handed branch represents a single branch, why it changes color after commit "0e5b5"?</p>
  
  <p>I searched for a tutorial on how to read git log graphs, unfortunately, I got nothing. If there are some awesome tutorials on this topic, please feel free to share.</p>