title: stack vs queuing?
body: <p>hello im still a student and im a bit confused about stacking and queuing ?
  first question is, </p>
  
  <ol>
  <li><p>what is the main diffrence between them two ?</p></li>
  <li><p>btw there is circular queuing beside normal queuing how about that ? how do they work ? is there any different ways to queuing?</p></li>
  <li><p>im useing php, is there a simple ( very simple or easy to read ) sample code that i can learn on ( links are okay too. )?</p></li>
  <li><p>there is pop, push and etc ( stacking and queuing ), is there anything like that in php ?</p></li>
  </ol>
  
  <p>Thank you very much for looking in.</p>