I'm really interested in building my own cnc machine. I've looked around online and I'm slightly confused. I see some kits that require a power supply, breakout board, stepper driver, and motor to run. And others, like zen tool works cnc, (to my knowledge) only needs power supply, breakout board, and motor to run. This leads to my question.
Why do some cnc machines need stepper drivers while others do not?
What does a stepper driver do?