title: Compare 2 Lists with a foreach Loop and create new List from items not found
body: <p>I apologize for posting such a seemingly simple question. I know there are many similar questions already posted (and I have looked at many of these before posting my question), but I struggle to apply the answers to my situation. I am relatively new to C#, and would appreciate your input and help. </p>
  
  <p>How can I compare my 2 <code>Lists</code> with a <code>foreach</code> loop, and create a new <code>List</code> with the records found that does not exist in my comparison?</p>
  
  <p>Below is the code outline I already have, and comments of what needs to happen:</p>
  
  <pre><code>private void updateHolidays()
  {
      List&lt;Holiday&gt; localHolidays = getLocalHolidays();
      List&lt;Holiday&gt; remoteHolidays = getRemoteHolidays();
  
      List&lt;Holiday&gt; holidayDifference = new List&lt;Holiday&gt;();
  
      foreach (Holiday holiday in remoteHolidays)
      {
          if (true) // holiday does not exist in localHolidays
          {
              // add holiday to holidayDifference
              holidayDifference.Add(holiday);
          }
      }
  
      createNewHolidays(holidayDifference);
  }
  </code></pre>
  
  <p>Thank you in advance!</p>