The PWM component returns a digital output that is switched high for a period related to the amplitude of a control signal, then switched low for the remainder of a predefined cycle time.

This type of signal is used to control systems that can only be switched on or off, but need more accuaracy than an on-off controller (like a thermostat), or where there is a lot of electromagnetic noise. They are also used to limit the time the system is switched on to avoid damage.