Output in instruments: What is the difference between active pulses and passive pulses? How to wire it? Contact output?

I understand the wiring; the contact output is equivalent to a relay, so please provide a more in-depth explanation! Thank you~~

With active pulse output, the operating power supply for the pulse signal generation circuit of the electricity meter is located within the meter itself; the generation and transmission of pulses do not rely on any other power source outside of that of the meter, and the corresponding pulse signals can be generated directly through the pulse signal generation circuit. The amplitude of the signal output by an active pulse is fixed; generally, the high level should not be lower than 0.9U0, and the low level should not be higher than 0.9V. A passive pulse output requires an external DC power supply as well as a pull-up resistor or pull-down resistor in order to generate pulse signals. The amplitude of its pulse signal depends on the applied DC operating voltage and the resistor. Follow the instructions for wiring; the contacts are the relay contacts