title: What is a multi-headed model? And what exactly is a 'head' in a model?
body: <p>What is a multi-headed model in deep learning?</p>
  
  <p>The only explanation I found so far is this: <em>Every model might be thought of as a backbone plus a head, and if you pre-train backbone and put a random head, you can fine tune it and it is a good idea</em><br>
  Can someone please provide a more detailed explanation.</p>