Is there a guide to the stat command output?

I’m trying to optimise the performances of my game, found this:
https://docs.unrealengine.com/latest/INT/Engine/Rendering/PerformanceProfiling/StatCommands/index.html
but no documentation about the output of the above commands.

Is there a guide to the stat command output, or even better, to optimising games through these commands?

Ok, no guide found, but this video [How to scale down and not get caught - The Unreal Engine 4 “Rivalry” Demo] has been quite helpful: