title: FileInputStream and ObjectInputStream
body: <p>I have to read in a file using these classes. 
  I don't really understand how they work.</p>
  
  <pre><code>FileInputStream inFile = new FileInputStream(fileName);
  ObjectInputStream inStream = new ObjectInputStream(inFile);
  car = (Car)inStream.readObject();
  </code></pre>
  
  <p>If car is a class, what exactly is being read?
  I'm so confused about this.</p>
  
  <p>car is an instance of the class Car</p>
  
  <p>Thanks</p>