• React is a JavaScript library for building user interfaces.
• JSX is a syntax extension for JavaScript used with React to describe what the UI should look like.
• npm: node package manager
• Package.json is configuration for npm
• There are two types of dependencies - dev dependencies and normal dependencies
• Parcel
  • Dev Build
  • Local Server
  • HMR (Hot Module Replacement)
  • File Watching Algorithm - Written in C++
  • Caching - Generate the build faster
  • Image Optimization
  • Minification
  • Bundling
  • Compres
  • Consistent hashing
  • Code Splitting
  • Differential Bundling - support older browsers
  • Diagnostic
  • Error Handling
  • HTTPS
  • Tree Shaking - Remove unused Code
  • Different dev and prod bundles
• start keyword is reserved by npm. So we dont need to user "npm run start". You can directly use "npm start"
• JSX React
  • JSX is not HTML in JS, HTML-like or XML-like syntax
  • JSX transpiled before it reaches the JS - PARCEL - Babel
  • React.createElement => ReactElement- JS Object => HtmlElement(render)
• React Component
  • Class Based component - OLD
  • Functional Component - NEW
• Component Composition -When you render one component into another component