А если уж серьезный вопрос

Question

То пожалуйста, для чего, почему и как я могу использовать JavaScript?

Answer 1

The most simple answer would be that js gives your website interactivity and dynamics. You can use it in both the front and back-end and even make apps with it.

Take a look :

https://developer.mozilla.org/en-US/docs/Learn/JavaScript/First_steps/What_is_JavaScript

Answer 2

good, thank you

Answer 3

Учи, узнаешь. :з