The Gecko website tells you all about high and low settings, servos or steppers work better correctly set up.
Once they are set up, you then use the "reverse" in ports and pins so when you press the X+,X-,Y+,Y-,Z+,Z-keys on your keyboard the axis goes the way you want it to on the machine. You can also do the same thing by swapping wires on the steppers for example, its just easier in software.