I'm one of the contributors of react-native-navigation. This question was a commonly asked, and I have written an answer before (as react-navigation VS react-native-navigation).

React-Navigation is Javascript-based navigation, that means all the navigate happen inside of single Activity (on Android and iOS counterpart).

The good part about Javascript based navigation is they will work on most platforms. But they usually suffer from performance issues due to stacks everything in the same activity.

React-Native-Navigation on another hand is actual native navigation. Every screen has its native container that handles native system. Better optimize better performance at the cost of deep integrate for each platform.

Hope this help.