Webpack is a tool that puts all your assets including images,javascript ,fonts and css in a dependency graph entry point: is the file webpack looks for to start building your Javascript bundle webpack’s main strength is code splitting. It introduce a production mode and development mode. As ,, Syntax of ReactJS is based on ES6. old browsers doesn’t understand ES6. So , to run JS we need something which transform our ES6 code to browser understand language , the same thing is done by babel-loader. Babel-loader is a webpack loader for transpiling ES6 and above , down to ES5. For this, you need three things - babel-core, babel-loader, babel-preset-env Commands- 1. npm init: This cmd create a package.json file . 2.npm i webpack --save-dev: This cmd generate dependencies for webpack in package.json file. Like "devDependencies": { "webpack": "^4.16.2" } 3. npm i webpack-cli --save-dev : This cmd is