JS_Async_Await
Sychronous is when something is going on, but you don't want to wait
until that thing is done to continue your program.
-> you want to continue while it's happening = Asychronously
Callback vs. Promise
Parameter callback is altered (delete).
And .then() will be used when calling the function!
Reference
- https://www.youtube.com/watch?v=PoRJizFvM7s (from Traversy Media)