Do GUI.Image instances use GPU memory (in full screen scene texture)?

Probably dumb question, I think I know the answer but want to make sure before I double down on anything - Do GUI images sit on the memory of the GPU itself the same way individual textures do? I think the answer is no because the entire texture is drawn on the canvas then that result is sent to the GPU, is that correct?

But if AdvancedTexture.CreateForMesh is used, and each of those textures contains an individual image, then they essentially do end up sitting on the GPU right?

Each AdvancedDynamicTexture corresponds to a GPU texture, but you are correct when saying a GUI.Image is blit in the canvas before the canvas being copied to the GPU texture.