title: Is Node.js native Promise.all processing in parallel or sequentially?
body: <p>I would like to clarify this point, as the <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/all">documentation</a> is not too clear about it;</p>
  
  <p><strong>Q1:</strong> Is <code>Promise.all(iterable)</code> processing all promises sequentially or in parallel? Or, more specifically, is it the equivalent of running chained promises like </p>
  
  <pre><code>p1.then(p2).then(p3).then(p4).then(p5)....
  </code></pre>
  
  <p>or is it some other kind of algorithm where all <code>p1</code>, <code>p2</code>, <code>p3</code>, <code>p4</code>, <code>p5</code>, etc. are being called at the same time (in parallel) and results are returned as soon as all resolve (or one rejects)?</p>
  
  <p><strong>Q2:</strong> If <code>Promise.all</code> runs in parallel, is there a convenient way to run an iterable sequencially?</p>
  
  <p><strong>Note</strong>: I don't want to use Q, or Bluebird, but all native ES6 specs.</p>