title: What do the return values of node.js process.memoryUsage() stand for?
body: <p>From the official documentation (<a href="http://nodejs.org/api/process.html#process_process_memoryusage">source</a>):</p>
  
  <blockquote>
    <p><strong>process.memoryUsage()</strong></p>
    
    <p>Returns an object describing the memory usage of the Node process
    measured in bytes.</p>
  
  <pre><code>var util = require('util');
  
  console.log(util.inspect(process.memoryUsage()));
  </code></pre>
    
    <p>This will generate:</p>
  
  <pre><code>{ rss: 4935680, heapTotal: 1826816, heapUsed: 650472 }
  </code></pre>
    
    <p>heapTotal and heapUsed refer to V8's memory usage.</p>
  </blockquote>
  
  <p>Exactly what do <strong>rss</strong>, <strong>heapTotal</strong>, and <strong>heapUsed</strong> stand for? </p>
  
  <p>It might seem like a trivial question, but I've been looking and I could not find a clear answer so far.</p>