title: What do parentheses mean in an #if defined preprocessor operator?
body: <p>(I am working on a SDK wherein I have the code of the particular SDK in reference and I am not able to trace out the flow of the program.)</p>
  
  <p>What does </p>
  
  <pre><code>#if defined (AR7x00)
  </code></pre>
  
  <p>mean? Specifically, what is the purpose of parentheses in a such a preprocessor operator?</p>