title: handling more than one request
body: <p>I am writing an ordering system.</p>
  
  <p>In this program, the user can request food. For this purpose I have a class named <code>User</code> and a class named <code>Food</code>.</p>
  
  <p>In the class <code>Program</code> I have a field  which is a list field that contains foods object.  In the class <code>Program</code> I also have a field of user object.</p>
  
  <p>Now I am a bit confused. The thing is if two users at the same time request order, do I need to use a list of users in my <code>Program</code> class or is the one field enough?  Or do I need to use threading.</p>
  
  <p>The way I have written the app, it just handles one request at the time. So what about further requests? What changes do I need to apply so it handles users' requests?</p>
  
  <p>I am not using any database at the moment (which I am not that much familiar with)</p>
  
  <pre><code>class User {
    private string name;
    private string address;
    // ...
  }
  
  class Food {
    private string name;
    private int id;
    // ...
  }
  
  class Program {
    private User user;
    private List&lt;Food&gt; foods;
    // ...
  }
  </code></pre>