How is the entire React Native code processed to show the final output on a mobile screen
* At the first start of the app, the main thread starts execution and starts loading JS bundles.
* When JavaScript code has been loaded successfully, the main thread sends it to another JS thread because when JS does some heavy calculations stuff the thread for a while, the UI thread will not suffer at all times.
* When React starts rendering, Reconciler starts “diffing”, and when it generates a new virtual DOM(layout) it sends changes to another thread(Shadow thread).
* Shadow thread calculates layout and then sends layout parameters/objects to the main(UI) thread. ( Here you may wonder why we call it “shadow”? It’s because it generates shadow nodes )
* Since only the main thread is able to render something on the screen, the shadow thread should send the generated layout to the main thread, and only then UI renders.
