How does stepper work? How to control its speed?How to use Grbl for CNC?calculations & connections

in this video you will learn
1.what's internal components of stepper motor
2.how does it work
3.how does stepper drive work
4.terminal and connections of stepper drive
5.how to control stepper speed using potentiometer
6.how to use grbl
7.how to add grbl library to Arduino IDE
8.how to use UGS
9.how to calculate stepper motor required torque for horizontal application