title: Bootstrap 3.1.1 - What is the .map extension file used for?
body: <p>I need to upgrade an application I'm working on with the latest Bootstrap version but I'm struggling to figure out what an addition of <code>bootstrap.css.map</code> is for?</p>
  
  <p>Do I need to have them to have the css work properly?</p>
  
  <p>I did some search before writing this but since it's relatively new,
  I haven't come across any tangible explanations to this.</p>