What is JavaScript , JQuery and DOM ?

In very Short and Simplified manner:-

JavaScript is Language.

JQuery is Library or Framework or Reusable which is built on top of JavaScript.

Basically JQuery works with 3-S i.e. Start ($), Selector (“.” or “#”) and Shot (Action i.e. Click or Val etc.)

 DOM  (Document Object Model ) - It is representation of HTML document  or piece of Web Page or HTML Content exist in the Web page having tags like <Div>, <P>, <Span>, <UI>, <LI> etc..

DOM is like standard object which consist HTML elements properties, HTML elements methods, HTML elements events

DOM - In-Memory representation of HTML

High Level structure of DOM: