Performance RAM and VRAM in UE4

I’m trying to clearly understand the usage of RAM and VRAM in ue4, so started digging using memreport, memreport -full, stat llmfull, -llmcsv, but when I try to calculate MB manually (from memreport and llm) my calculations don’t much the memreport and llm information.
For example, I took screenshot from a test build.

I have a few questions (correct me if I am mistaken in my decisions):

  1. WorkingSetSize (from llm full) and Process Physical Memory (from memreport) is it RAM?
  2. If I try to sum lines info (below line WorkingSetSize) I get a number equal to Tracked Total, which is not equal to WorkingSetSize. What the difference between the two?
  3. RHI resource memory from mem report is it VRAM?
  4. What information does RAM and VRAM contain?

Yes and what exactly is PageFileUsed?