using async.parallel vs async.each

async.each.js

async = require("async");
var results = [];

async.each(states,
  function(state, callback){
     var url = baseUrl + state.name;
     request(url, function(err, res, body){
        results.push(data);
        callback();
    });
  },
  function(err){
    //done, now save results.
    store.save(results);
  }
);

async.parallel.js

async = require("async");
var asyncTasks = [];
var results = [];

states.forEach(function(state){
  asyncTasks.push(function(callback){
    var url = baseUrl + state.name;
    request(url, function(err, res, body){
      results.push(data);
      callback();
    });
  });
});

// Execute tasks simultaneously
async.parallel(asyncTasks, function(){
  //done, now save results.
  store.save(results);
});