The Complete React Developer Course (with Hooks and Redux) - Babel Polyfill

The video tutorial explains the importance of using Babel Polyfill to ensure JavaScript applications run smoothly across various browsers, including older ones like IE11. It demonstrates using BrowserStack for cross-browser testing and shows how Babel converts modern JavaScript code for compatibility. The tutorial guides on integrating Babel Polyfill into a project using Webpack, ensuring features like 'includes' work in unsupported browsers. Finally, it tests the application to confirm successful integration.

What issues might arise when using modern JavaScript features in older browsers without Babel Polyfill?

Explain how Babel Polyfill can affect the deployment of a web application.