title: Bootstrap 3.0 Grid Explanation
body: <p>Can someone explain Bootstrap 3.0 Grid system. I have been using Bootstrap v2 grid which had simple span1 to span12 for columns. Now Bootstrap 3.0 has different types of columns sizes like .col- .col-sm- .col-lg-</p>
  
  <p>I found this example: <a href="http://examples.getbootstrap.com/grid/index.html" rel="noreferrer">http://examples.getbootstrap.com/grid/index.html</a>, but It has many different ways, like I could not understand the "Mixed: mobile and desktop" grid where .col-12 .col-lg-8 are together.</p>
  
  <p>I hope to migrate my Bootstrap v2 website to Bootstrap v3, but finding these changes too much.</p>
  
  <p>Please explain.</p>
  
  <p>EDIT:
  Also got this nice article explaining Bootstrap 3 Grid (this article came after I asked my question here. Hope it helps future readers): <a href="http://blog.jetstrap.com/2013/08/bootstrap-3-grids-explained/" rel="noreferrer">http://blog.jetstrap.com/2013/08/bootstrap-3-grids-explained/</a></p>