Windows 10 power slider: What exactly does it do, and how to change it?

Question

The first part of the question would be what exactly each of these settings does. For the power plans, I am able to check and set each of the plans own settings (like max CPU clock, usage, time till sleep). Now I can't even figure out what exactly each setting does, in terms of Voltage, Amps, Clocks, and max usage. In numbers. And how can I change this?

Also, it seems like the best performance mode overrides my power plans. I have set my max Frequency to 2000 MHz, but in best performance mode this will be ignored and my CPU will clock to it's normal 2800 MHz often, untill I turn the plan down to recommended or better performance. Is this a bug, or a feature?