title: Rails content_tag vs tag
body: <p>What's the difference between <code>content_tag</code> and <code>tag</code> in Rails? From what I've read, it seems that <code>content_tag</code> requires content to be passed to it. </p>
  
  <p>Why does this matter? What's different syntactically, as well as what cases would I use one vs the other?</p>