What does the game send to GPu and not CPU

[Oizu]

Im no expert but from what i understand, the game sends quite a lot of things (like shadows) to the cpu, where as a modern game wwould most likely send this to the GPU, so my question is, since i have aquite a slow CPU, what things DO go to the GPU, because ive got a pretty good graphics card, and im fairly sure tghe things that do go to the GPu id be able to crank up to max, im guessing textures, but what else?