title: How do prototypes work under the hood?
body: <blockquote>
    <p>"Put functions on a prototype object when you're going to create lots
    of copies of a particular kind of object and they all need to share
    common behaviors. By doing so, you'll save some memory by having just
    one copy of each function, but that's only the simplest benefit."</p>
  </blockquote>
  
  <p>How exactly does this work under the hood?</p>