What is React Native?
It allows you to build mobile applications that look, feel and perform much more like native applications. It uses the same fundamental GUI building blocks as iOS and Android native apps. We need to use those building blocks using javascript and react.
React uses virtual Dom however react native there is no DOM instead native components which provided by platforms such as iOS and Android. There are no web views here then how does work with Javascript?
React native has an instance of JavascriptCore to execute JS code when an application starts. React native uses RCTBridgeModule to make a connection between native code and javascript code.