title: Difference between the main and the test folder in Maven
body: <p>I am a bit confused on the difference between the use of the folder main and the folder test in Maven. As of now, I just copy and paste my source code in both of them and it works fine. I don't get what the point of having another folder with exactly the same thing as the main folder is? Can someone please explain this to me.</p>
  
  <p>Also:</p>
  
  <ul>
  <li>What is the difference between install and compile.</li>
  <li>So for this command: mvn archetype:generate, is generate the goal? then what is archetype?</li>
  </ul>
  
  <p>Thanks</p>