title: NodeJS: Parallelism of async module
body: <p>I am following the async module's each method (<a href="https://github.com/caolan/async#each" rel="nofollow">https://github.com/caolan/async#each</a>). It says the method iterates over the array parallely. "<strong>Parallely</strong>" is the word that confuses me. AFAIK, in now way JavaScript can execute code parallely because it has a single-threaded model.</p>
  
  <p>The examples shown in the each method focuses on the IO scenarios. I am using the "each" method just to add numbers of the array. If parallelism exists, can I prove this using my example?</p>
  
  <p>Thanks for reading.</p>