Runs the app in development mode. Will open the http://localhost:3000 to preview changes in your default browser.
The page will automatically reload if you make changes to the code. You will see the build errors and lint warnings in the console.
npm run build or yarn build
Builds the app for production to the build folder. It correctly bundles React in production mode and optimizes the build for the best performance. The build files will be minified and the filenames will include the hashes. Your app is ready to be deployed.