Purpose of high side in a half bridge?

[HellTriX]

Quick question.
What purpose does the high side mosfet of a half bridge serve?

rephrased:

If my load is connected from Vcc to the Drain of the lowside, what does the high side do on the opposite pwm input signal?

tnx

 

[3v0]

You are using it as if it were a single transistor.

The idea behind a half h-hbridge is that you can switch between + and GND.
Like a SPDT switch.
If you put one on each terminal of a DC motor you can run the motor in both directions.

Lots of info on the web. Google for it...