In the finally() method if i type 'event.target.remove()' without it being an arrow function what will happen ?

Hi Alexander!

Not using an arrow function will throw the timing off.

In this case, you want to use a callback function (which delays execution of that function until an appointed time, in this case, not until finally() executes).

I recommend taking this course to fully understand how callback functions work and why you should use them:

https://teamtreehouse.com/library/callback-functions-in-javascript

Also, I came up with this to help better visualize how callback functions work:

const square = function(num) {
  return num * num;
}

const quad = function(func, num) { // func being the callback function as a perameter (a function variable)
  return func(num) * func(num);
}

console.log( quad(square, 3) ); // square being the callback function as an argument function

Which, in this case, will log 81 to the console.

Note in this case the execution of square is delayed until quad is called (hence its "callback"-ness!?!).

I hope that helps.

Stay safe and happy coding!