title: Difference between frontend, backend, and middleware in web development
body: <p>I was wondering if anyone can compare/contrast the differences between frontend, backend, and middleware ("middle-end"?) succinctly.</p>
  
  <p>Are there cases where they overlap?
  Are there cases where they MUST overlap, and frontend/backend cannot be separated?
  In terms of bottlenecks, which end is associated with which type of bottlenecks?</p>