Have this BP with a cylinder component, which has relative rotation X = 20
So the cylinder is rotated 20 degrees around X (red) axis from the parent reference frame.
The reference frame (gizmo) shown above is the relative (parent’s) reference frame.
If I add a relative Z rotation to cylinder, it’s gonna rotate around that blue axis :
Now this is the cylinder’s local reference frame :
If I add the same Z rotation as a local rotation, it’s gonna rotate around cylinder’s blue axis, which results in this :
