From Shopbot Wiki
CONTROL SOFTWARE: The ShopBot control software is the program that you install on your computer that communicates with your ShopBot's Control box. It is NOT one of the programs that you would use to design your project or create part files to cut the pieces (like Part Wizard), but it IS the program that you use to cut your Part File or to view your Part File in Preview Mode.
FIRMWARE: Firmware is a program that is installed into the micro-controller of a piece of hardware like your ShopBot Control Box. It's different from most programs like the ShopBot Control Software because the user doesn't usually interact with it and might not even be aware that it exists. One example of firmware is the BIOS that runs the lowest-level processes in your computer and is installed on a chip on the motherboard.
MICROSTEPPING: Although steps are defined and fixed for a particular motor, some motor drivers can divide them into smaller units in a process known as microstepping. Microstepping smooths the motion of a stepper motor.
STEPS: A stepper motor's movement is broken down into individual small movements. Each one of these movements is called a "step", and is the reason that we can make precise movements with CNC tools.
UNIT VALUES: The setting in the ShopBot Control Software that defines how many steps to move for a unit of distance, distance being either an inch or a mm depending on current setting. For example, if the tool Distance setting is Inches, a Unit Value of 1800 would indicate that exactly 1800 steps are required in order to move the axis 1 inch.