Thank you Neale, I actually understood quite a lot of what you say even on 1st reading but I will refer back to it as my knowledge hopefully grows and it will make more sense.
I don't think I will ever truly understand electronics, I would love to but I just don't think my brain is wired that way.
I particularly like your use of Analogies (induction) and would ask you to try and assist me with one..
Here goes..

I am in a Car driving up an endless flight of stairs, step by step..
I (my brain) is Mach3 sending information to my hands and feet (Gcode).
The Engine (Stepper motor) is on and I am in 1st gear (Manual gearbox) and my front wheels are sitting on a step while the rear wheels are in-between steps sitting on the nosing of a tread. I am 'riding' the clutch to stop me rolling backwards.. ie the stepper is using ('Gas') electricity to hold it's position..
I wish to move up the steps so I need to send information to my accelerator foot to give just enough Gas (pulse) to move the front wheels up to the next step.. (a line of gcode..) and, Stop.

The variables are many.. Do I have a large Car with a very small engine.. or a Veyron FU..
How good is my clutch.. How good is my clutch footwork..
What fuel am I using, Diesel will generally give better torque than petrol.
Do I have an Old Car that has Carburettors or a newer one with Injection and engine management systems..

I am trying to equate this analogy with the path through from Mach3 to Motor..
So..
1st problem to me is making sure all the separate components actually work.. and then, are they compatible with each other..
Assuming they all are & do, then joining all the wires to their correct home seems well documented and reasonably straightforward.
Configuring the system I think comes next..?
If continuing with the Car analogy then this system seems to relate back to Model T Ford era where each element has to be set in the correct order, Ignition on, fuel pumped, magneto magnetoed (no idea..) apply Choke (and I'm sure, lots of other jobs) prior to starting the Motor.. Then, as you trundle off, modifying things as you go..
(Rather than modern Cars with their 'Key In and Go' simplicity.)
I feel this is similar to the complex 'setting up' process with CNC Machine Building. Is this reasonable?

I have run out of Analogies but perhaps you could offer (or direct me to) your particular story of how you chose what you did and why and how you the put all the pieces together.

I am concerned that many of the Build Logs are quite old now and I don't know if new products/knowledge have superseded them..
Also..
Are there some critical measurements that can be proffered by newbies like myself.. Like, Table size, weight of Gantry or ? to assist the Elders in guiding us to relevant information..

Thanks again Neale for your help.