title: Whats the difference between ForwardRefExoticComponent and ForwardRefRenderFunction in react?
body: <p>I'm writing a React component which can forward ref to its chilren</p>
  <p>I found out that for the return type of the function components, I can use <strong>ForwardRefExoticComponent</strong> and <strong>ForwardRefRenderFunction</strong>. But I'm not sure whats the difference between them.</p>
  <p>So far, When using <strong>ForwardRefExoticComponent</strong>, I can extend it while the <strong>ForwardRefRenderFunction</strong> cannot? I posted a question related to my case here : <a href="https://stackoverflow.com/questions/64236857/how-to-export-forwardref-with-forwardrefrenderfunction/64237782#64237782">How to export forwardRef with ForwardRefRenderFunction</a></p>
  <p>If anyone know whats the difference between them and what they do please help me. Because it seems that React team has no document about them (but they are inside react package)</p>