Watt and VAR (volt-ampere reactive) are both units of measurement used in electrical engineering to describe the flow of electric power.

Watt (W) is the unit of measurement for real power, which is the actual power that is being used to perform work. It is a measure of the rate at which energy is being consumed or produced. One watt is equivalent to one joule of energy per second.  Our controller of power would be:  T4800

VAR (volt-ampere reactive) is the unit of measurement for reactive power, which is the power consumed or produced by reactive components such as capacitors and inductors. Reactive power does not perform any actual work, but it is necessary to maintain the voltage and current levels in an electrical system. One VAR is equivalent to one volt-ampere of reactive power.  Our controller of reactive power would be:  T4900

In summary, Watt measures the actual power that is being used to perform work, while VAR measures the reactive power that is necessary to maintain the voltage and current levels in an electrical system.