1. Key Difference 1: Module Bundler Compatibility

   • @babel/polyfill: It is compatible with all module bundlers and can be directly imported into the code.
   • core-js: It requires additional configuration when used with module bundlers like Webpack, as it needs to be included in the polyfills section of the configuration file.

2. Key Difference 2: Polyfilling Global Objects

   • @babel/polyfill: It polyfills global objects such as Promise, Set, and Map by modifying the global environment.
   • core-js: It provides modular APIs to polyfill global objects, allowing more flexibility in polyfilling only specific features.

3. Key Difference 3: Targeted Polyfills

   • @babel/polyfill: It includes all polyfills regardless of the target browser, resulting in a larger bundle size.
   • core-js: It allows the selection of specific polyfills based on the target environment, resulting in a smaller bundle size.

4. Key Difference 4: Customization Options

   • @babel/polyfill: It does not offer explicit customization options and provides a pre-determined set of polyfills.
   • core-js: It offers more customization options, allowing developers to choose specific polyfills or configure polyfill usage based on different criteria.

5. Key Difference 5: Browser Compatibility

   • @babel/polyfill: It ensures broader browser compatibility by including necessary polyfills for older browsers.
   • core-js: It provides a more modular approach, allowing developers to target specific browsers and include only necessary polyfills.

6. Key Difference 6: Maintenance and Updates

   • @babel/polyfill: It is no longer actively maintained and is recommended to use core-js for future projects.
   • core-js: It is actively maintained and regularly updated, providing bug fixes, performance improvements, and new features.

In summary, @babel/polyfill and core-js differ in their module bundler compatibility, polyfilling approach, target customization options, bundle size impact, browser compatibility, and maintenance status.