title: Java OutOfMemoryError Exception
body: <p>I'm confused on what OutOfMemoryError really is.</p>
  <p>The question I have asks what the OutOfMemory exception signifies:</p>
  <ol>
  <li>The process ran out of heap space</li>
  <li>Process ran out of physical memory</li>
  <li>Operating system ran out of virtual memory.</li>
  </ol>
  <p>I have looked around online and there are many different answers for both number 1 and 3. I'm leaning towards answer 1 but I'm not so sure.</p>