title: What is the difference between async.map or async.each with async.parallel?
body: <p>I started working on a node project recently and have been using the <code>async</code> library a lot. I'm kind of confused as to which option will be faster. Using <code>async.map</code> on some data and getting its results or using <code>async.each</code> to iterate over an array of users and put their corresponding operation into an array of function calls which I execute using <code>async.parallel</code>.</p>