How is the entire React Native code processed to show the final output

1.	How is the entire React Native code processed to show the final output on a mobile screen
Answer» 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.

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