title: Semantic UI Grid Classes
body: <p>In most CSS frameworks grid classes are clearly defined for example Bootstrap has</p>
  
  <pre><code>xs (for phones)
  sm (for tablets)
  md (for desktops)
  lg (for larger desktops)
  </code></pre>
  
  <p>Reading through Semantic UI it does not seem to have to grid class, does anybody know what they are?</p>