Behind the Scenes,React Native

Above explains the internal working of the react native application. Where the code can be divided in two parts such as special components(..etc) and the JavaScript code. Now the special components are only compiled to native views and not the JavaScript code. The JavaScript code is kept separately and is written according to the business logic. Now we can use the API native component such as camera because the JavaScript code runs internally in your app ,where we have virtual JavaScript machine running internally by react native. This virtual machine knows how to talk to native machine by using bridge present internally inside react native application.

The native views which can be on any native platform iOS or Android can be used by writing a single code.This reduces the cost of the application and hence is preferred more these days..

Hope it was helpful!