title: Front-end performance and number of css/js files
body: <p>I am trying to find an answer as to how to improve front-end performance for web applications. My question is say I have multiple css/js files being referenced.
  Now the browser would make http call for each of the css/js file. But my questions are;</p>
  
  <ol>
  <li>Does it happen in parallel or happen one after the other ? Is it same for both CSS/JS ?</li>
  <li>Is the behaviour (parallel or one after the other) browser-specific ? </li>
  <li>Is the use of async attribute for script tag standard or accpeted way for asynchronous download?</li>
  <li>Are there any limitations to the number of http calls that can be made for a single page ? Is it browser-speicific?</li>
  <li>Does using AMD frameworks like RequireJS solve any of the performance issues OR is it to be used only in a single-page app development ?</li>
  </ol>
  
  <p>Apart from that references to any other general front-end performance improvement tips would be great?</p>