IGPU and DGPU

So IGPU was borrowing ram to render graphics, display images and more from the system and the system said they had limited RAM so it can only borrow a few ram and then next for the DGPU, The DGPU builled IGPU cause the IGPU has the worse performance in Heavy gaming, struggling to get high FPS cause DGPU has its own memory, better FPS and Gaming performance than IGPU do DGPU said the IGPU is only just for schoolwork, Gaming light to moderate and the IGPU sucks