title: How does the getView() method work when creating your own custom adapter?
body: <p>My questions are:</p>
  
  <ol>
  <li>What is exactly the function of the LayoutInflater?</li>
  <li>Why do all the articles that I've read check if convertview is null or not first? What does it mean when it is null and what does it mean when it isn't?</li>
  <li>What is the parent parameter that this method accepts?</li>
  </ol>