JavaScript is the most popular web developing site in the world.
It is used for creating mobiles applications(IOS and Android both), desktop softwares and Webpages, etc. It is also used to make games with highly secured functions. It is very popular in mobile application because it is very quick to learn, if you have basic knowledge of computer and web developing. It is also popular in programming language.
Java Sccript is used by best companies in the world like Facebook, Google, Microsoft, etc websites asre built with JavaScript.
Program is a bulk of set of script of code in which the code is written by the programmer, this script of codes is instruct the computer or the website.
Script is a set codes which are written with the TAGS
In HTML, JavaScript code is written between the tags like shown in below:-
Mainly it is placed in the HTML page like shown in below:-
You can write the script tag between either The Head Tag or The Body Tag.