title: When does a function get added to the call stack?
body: <p>Lets say we have a sequence of functions being executed in the global scope, like so:</p>
  
  <pre><code>function second() {}
  
  function first() {
    second();
  }
  
  first();
  </code></pre>
  
  <p>When does <strong>first</strong> get added to the call stack?</p>
  
  <p>Does it get added upon invocation, or does it get added <em>after</em> it calls <strong>second</strong> (and the execution context is now inside of <strong>second</strong>)  ?</p>