A native runtime: A native binary that is built with Xcode or Android Studio. Expo Go is an example of a native runtime for developing React Native apps.
When your project requires custom native code, a config plugin, a custom runtime version, or a reduced bundle size of the app, you can transition from using Expo Go to develop to a development build.
A development build of your app is a Debug build that contains the expo-dev-client package. Like a production build is for the general public, and a preview build lets your team test your next release, a development build lets developers iterate as quickly as possible. It comes with extensible development tools to develop and test your project.
You can think of a development build as your own version of the Expo Go client.