How does a voltage controller specifically L7805CV work ( detailed )?
Does this simplified circuit help?







simulate this circuit &ndash; Schematic created using CircuitLab

The specifics of the internals is basically the above and is published in the data-sheets. If you can't recognize common circuits in the actual 7805 schematic, and figure out the details of the complex internal circuitry, then I am afraid it is far too complicated to detail here.

There are numerous links already given in the comments here, and in the duplicate question, that will get you on your way though.