What is DOM, Shadow DOM and Virtual DOM?

 https://www.blog.duomly.com/what-is-the-difference-between-shadow-dom-and-virtual-dom/

DOM - Document Object Module

Shadow DOM - DOM components

Virtual DOM: Virtual DOM is a concept of DOM used by React.js and Vue.js. In Virtual DOM concept copy of DOM is saved in the memory and while any change is done in the DOM, it’s compared to find differences. Then browser knows which elements were changed and can update only those part of the application to avoid re-rendering all the DOM.