title: Angular or Bootstrap for responsive UI and front end validation
body: <p>I am developing an frontend using Angular. I want to develop a responsive front end. I have the following queries:</p>
  
  <ol>
  <li><p>Can I develop a responsive UI using Angular alone without using responsive attributes of HTML5 and BootStrap? Or do I need to use Bootstrap and HTML5 to make my frontend responsive?</p></li>
  <li><p>I know we can implement UI client side validation using Bootstrap or HTML5 and/or Angular. So while developing the front end which framework should be used for implementing validation?</p></li>
  <li><p>Is there any valid reason to use Bootstrap, while developing a front end using Angular? If so, then for which functionality in particular?   </p></li>
  <li><p>Why is Angular development termed as a mobile first approach?</p></li>
  </ol>