The ratio between the KW of the load and the KVA of the load.
The real power in the load in thousands of watts.
Single phase KW = V x A x pf / 1000
Three phase KW = Vp x A x pf x rt3 / 1000
The apparant power in the load.
Single phase KVA = Vrms x Arms
Three Phase KVA = Vrms x Arms x rt3
The reactive power is the apparent power in the reactive current.
This is essentially the KVA with the reactive current only considered.
The reactive power does not include any KW component.
Displacement correction is usually rated in KVAR.