title: What do raw.githubusercontent.com URLs represent?
body: <p>I want to learn how to use <a href="https://rawgit.com/" rel="noreferrer">rawgit.com</a> to serve other applications from <code>github.com</code>.
  So we have a usual way to download and install <code>homebrew</code> on osx.</p>
  
  <pre><code>ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
  </code></pre>
  
  <p>I can't find the <code>install</code> file on GitHub. Where is it?</p>