Timeline View - Memory Utilization

I would like to know more about “Memory Utilization” in the Timeline View.
Three items displayed: “Local”, “Non Local”, and “Local Demoted Memory”.

I believe that “Local” means VRAM, and “Non Local” means system RAM, but what does “Local Demoted Memory” mean? (paged out to disk?)
When “Local Demoted Memory” is present in “Memory Utilization”, the app gets very heavy stuttering.