title: Android drawable folders fallback rule
body: <p>I'm trying to understand how the drawable folders in Android works. I found that in the resource folder in our project, it has the following folders:</p>
  
  <pre><code>res/drawable-ldpi/
  res/drawable-ldpi-v8/
  res/drawable-ldpi-v11/
  res/drawable-mdpi/
  res/drawable-mdpi-v8/
  res/drawable-mdpi-v11/
  res/drawable-hdpi/
  res/drawable-hdpi-v8/
  res/drawable-hdpi-v11/
  res/drawable-xhdpi/
  res/drawable-xhdpi-v8/
  res/drawable-xhdpi-v11/
  res/drawable-xxhdpi/
  res/drawable-xxhdpi-v8/
  res/drawable-xxhdpi-v11/
  </code></pre>
  
  <p>Can someone please educate me on how the fallback mechanism on these folders works? Also what does v8 and v11 mean?</p>