I don't know about yours, as I don't know where you are or what type of meter you are using, but for mine it is a direct reading. You note the numbers at the beginning of the month, and then again at the end, and the difference is the KWh used.
Kilowatt hour meter and kilowatt hour reactive meter both are same but kilowatt hour is used to measure the active energy and kilowatt hour reactive is a unit used for the reactive enrgy measurement