title: Boxplots in matplotlib: Markers and outliers
body: <p>I have some  questions about <a href="http://matplotlib.org/examples/pylab_examples/boxplot_demo.html" rel="noreferrer">boxplots</a> in matplotlib:</p>
  
  <p><strong>Question A</strong>. What do the markers that I highlighted below with <strong>Q1</strong>, <strong>Q2</strong>, and <strong>Q3</strong> represent? I believe <strong>Q1</strong> is maximum and <strong>Q3</strong> are outliers, but what is <strong>Q2</strong>?</p>
  
  <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <img src="https://i.stack.imgur.com/FBqdp.png" alt="enter image description here"></p>
  
  <p><strong>Question B</strong> How does matplotlib identify <strong>outliers</strong>? (i.e. how does it know that they are not the true <code>max</code> and <code>min</code> values?)</p>