A collection of name/value pair.

Object sits in memory as pointing to a particular spot or address in memory.

It's time for a JavaScript aside.

Let's talk for a moment about an important,

fundamental, and incredibly powerful aspect

of the JavaScript programming language

that Node relies upon,

and one that's often misunderstood: first-class functions

and function expressions.

Oh, actually, big word alert.

First-class functions: everything you can do

with other types, like strings or numbers,

you can do with functions.

A lot of major programming languages

do not have this feature.

JavaScript does.

V8

The JavaScript Engine

In this guide, I'm going to walk through exactly how we can work with promises in JavaScript.

However, before we can talk about this, I want to give more of a explanation on what promises are.

And thankfully, because of the way promises were created and how it's named, it's pretty easy and

straightforward to compare it to a real world scenario, and that is of a promise in real life.

So imagine that I come to you and I say that I am going to mow your lawn.

Now, that is a promise that I've made to you.

In this guide, we're going to get into how to work with asynchronous behavior in JavaScript.

And we're specifically going to talk about the concept of higher order functions and callbacks.

And both of these are integral parts of how to create that asynchronous behavior that we've talked about

in the very beginning of the guide.

So for this, I'm going to start off by creating a method, and this method is going to be considered

a callback method.

Now, a very important thing to know about callbacks is that they are just methods.