Once i created a build from my project i decided to take a look at the JS file produced in the build process and i found uglified code that i couldn't understand but at the first glimpse it seems that there is much code added by React that will work in the browser!

Now i am confused about what is the part of React that works in the browser, is the whole library added to the build file or certain functions from React + my code??

I understand that JSX part need to be compiled to work in the browser but what about other react functions, how they looks like after build?? how are they used by the browser??