I'm leaving the course right now, the profile.js section not being explained is really confusing.

//Here at the top of the file you are requiring some core modules from node.js
//what it does: it 'imports' some core functionalities from node.js
//EventEmitter: The base 'class' for your  'custom' event emitter
var EventEmitter = require("events").EventEmitter;
//https: Allows you to make https calls to other resources (here our own made up api)
var https = require("https");
//util: is used so you can extend EventEmitter and create your own 'child' class of it.
var util = require("util");

//Now create our own 'class constructor'. We do this so later in our application we can instantiate our eventemitter.
function MyOwnEmitter() {
      //Call the Node.js EventEmitter constructor (you need to do this so you can inherit from it later)
      EventEmitter.call(this);

      //We create a local variable 'self' which just refers to itself so we do not create any scoping issues when doing our api call
      var self = this;

      //let's do our api call to some made up api that returns weather data, by using the https module from above.
     //first parameter: the url we are requesting. second parameter: a callback function to run after the request is made
      var request = https.get('https://someMadeUpWeatherApi/', function(response) {
                     //set the body just to an initial string initially
                     var body = "";
                     //Here we listen for the 'data' event and add to the body as the data is coming to our server
                     response.on('data',function(chunk){
                           body += chunk;
                           //HERE IS KEY: WE ARE ACTUALLY EMITTING OUR OWN EVENT NOW
                           self.emit('dataFromMyApiIsHere', chunck);
                     });

                    //Here we listen for the 'end' event which is fired once our response is done. Which means we can parse the data
                   response.on('end',function() {
                         //parse the body into json so we can easily read it wherever we want to later
                         var json = JSON.parse(body);
                         //HERE IS KEY: WE ARE ACTUALLY EMITTING OUR OWN EVENT NOW AGAIN
                         self.emit('endOfOurApiData', json);
                   });
      }

}

//Here we inherit from EventEmitter so our 'class' MyOwnEmitter can use all of the same methods as EventEmitter. like //'emit' and 'on' as we have already seen above in self.emit etc.
util.inhertis(MyOwnEmitter, EventEmitter);

//export our class/module so we can use it in other files
module.exports = MyOwnEmitter;

var myOwnEmitter = require('./MyOwnEmitter.js');

//now we instantiate our own emitter;
//What happens at this moment -- it runs through everything we put in the function MyOwnEmitter above. 
//Including the api call to our made up weather api
var myOwnEmitterInstance = new myOwnEmitter();


//Now we can listen for the events 'dataFromApiIsHere' and 'endOfOurApiData' we emitted above
myOwnEmitterInstance.on('dataFromApiIsHere',function(chunk){
         console.log(chunck);
});

myOwnEmitterInstance.on('endOfOurApiData',function(json){
         //this will actually be all of the data our weather api returned in json format!!!
         console.log(json);
});