title: What is the purpose of the <nav> tag
body: <p>I have read a whole bunch of questions regarding where and how nav tags should be used and 
  I get that we are meant to put "major" navigational elements within it but what is it's purpose? </p>
  
  <p>I can see that <a href="http://www.w3schools.com/tags/tag_nav.asp" rel="noreferrer">w3schools</a> says that</p>
  
  <blockquote>
    <p>"Browsers, such as screen readers for disabled users, can use this
    element to determine whether to omit the initial rendering of this
    content."</p>
  </blockquote>
  
  <p>but does it have any further use, are there any other implications of omitting the <code>&lt;nav&gt;</code> tag?</p>