So a regular microwave turns the magnetron on and off for varying periods of time. Like if you wanted a minute at 50% power, it might turn the magnetron off for 10 seconds, then on again for 10 seconds etc to get 50%.
An inverter would apply 50% less power, but it would be constant power not intermittent. Sort of like PWM if you’re familiar with that?
Sorry. Not great at explaining it!
I was wondering this myself.