title: What is the difference between an atom and a symbol in Common Lisp?
body: <p>Are there any differences between what in Common Lisp you'd call an atom, and a symbol?</p>
  
  <p>Do these differences extend to other languages in the Lisp family? </p>
  
  <p>(I'm aware that atom has a different meaning in Clojure, but I'm interested in the boundaries of what is a symbol.) </p>