What is the difference between package.json main and app.config.js expo.entryPoint?

Question

I'm new to TypeScript, React Native and Expo, and am confused how you configure the main entry point.

This SO question talks about both configuration properties.

The Expo docs also mention both:

user_3156644 · Answer

package.json main is used as a fallback to the app.config entryPoint. You should be defining the entry point in app.config.

You can see how it has been handled here: https://github.com/expo/expo-cli/pull/750/files, and you can see a discussion about this change here