Can't understand rotations pivot points

Questions
2

hi
normally rotation work on the local pivot ( 0,0,0 )
https://playground.babylonjs.com/#ZIBQC3#2

i use parent child system for make local rotation
https://playground.babylonjs.com/#ZIBQC3#3

but you can manage that by pivot too
https://playground.babylonjs.com/#ZIBQC3#5