It means this product is a power supply adopting a PFC circuit.

PFC stands for Power Factor Correction, that is, a circuit to correct power factor by shaping the input current waveform into a waveform following the input voltage (bringing the input current waveform close to a sign wave).

A low power factor causes apparent input power higher than that actually consumed (efficient electric power) to increase the input current, resulting in no effective use of power distribution facilities.

PFC, when it is built in, also serves to suppress harmonics which is called "electric pollution".

Furthermore when the active filter method is adopted, the worldwide input between AC 100 V and AC 240 V will be available.