01_Introduction

1) . INTRODUCTION - REACT JS

•  React is java Script Library For Building UI

•  React is Use to Build Single-Page-Application

•  React Allow Us To Create Reusable UI Components

•  React is Free And Open Source Library

•  React is Declarative , Efficient And Flexible JavaScript Library For Building User  Interface. It Lets You Compose Complex UIs From Small And Isolated Piece Of  Code Called "Components"

•  React Sometimes referred to as a Frontend JavaScript Framework , is a  JavaScript Library Created By Facebook

•  React is a tool for Building UI Components.

1.1) What is React ?

•  React Community Also Provides Advance Concept Like State Management , routing , etc., on Top Of The React Library.

1.2) How Does React Works ?

•  React Creates a VIRTUAL DOM in Memory.

•  Instead of Manipulating the browser's DOM directly , React Create a virtual DOM  in Memory , Where it does All the necessary Manipulating , Before Making the Changes in the Browsers DOM.

1.3) React History

•  React Was First Used in 2011 for Facebook's Newsfeed Feature

•  Initial release to the Public (V0.3.0) Was in July 2013

•  Author - Jordan Walk (Facebook Software Engineer)

1.4) Declarative Approach (Abstraction Method)

•  You Can Tell the Browser what to do , instead by saying What's you Need , React Declarative Approach(Data Hide) is an Abstraction For Us.