The Boring Thread

[Marc G]

I hope you agree on that

No, there are processors that shutdown part of the CPU if these are not required. I'm not sure if the latest Intel CPU have this feature, but it was certainly announced by Intel.

I believe that a computer processor is always busy executing some code or the other, if not anything else Idle process running so what does 86% say usage actaully mean?

There is an "Idle process" but it doesn't really do anything. It doesn't use the FPU, ALU, whatever of your CPU.
So if it says 86%, then the CPU is performing 86% real work and in the remaining 14% it can be in a halt state.