title: What is the difference between global variables and #define in c
body: <p>Whats the reason why there are 2 opportunities :  </p>
  
  <ol>
  <li>global variables </li>
  <li>symbolic constants with <code>#define</code> ?</li>
  </ol>
  
  <p>So I know what <code>#define</code> does but I don't know what the difference in use is.
  Which situation do I must have thus I'm able to decide myself upon the right opportunitie? What is one of the opportunities able to do what the other one doesn't ? I hope that I could clarify what I mean.</p>