Power factor or efficiency ?

Many users confuse these terms or lump them together.

However, they are two different properties. The power factor (= cosφ) describes the proportion of reactive power caused by inductive or capacitive loads in the operating device. There are normative regulations depending on the power. The efficiency factor, on the other hand, is more of a quality characteristic of an LED driver, for example, and provides information about the efficiency. An efficiency of 80% or 0.8, for example, means that 80% of the power fed in on the mains side (primary) is used on the output side (secondary). Only 20% is lost as heat losses in the driver. (Good: > 90%, average between 80% and 90%, bad: < 80%)