Can anyone explain servo motion control

[swdias]

I built my first 2x4 router using steppers and it's works great, thanks to the huge library of information from everyone on this board! I don't think there is anywhere close to this much info anywhere else.

I'm still wanting to know more about servos, my research has left mostly just alot of questions and holes in my mind when it comes to servo control. Maybe it's just my search skills are lacking.

Can anyone sum up:
Servo amplifier
Servo Drive
Servo controller
AC or DC servos
Do you need all of these to control an axis?
Can they be controlled via the parallel port using EMC2 or Mach3?

It doesn't appear to be anywhere near as obvious as stepper drivers boards and power supples leading to parallel port.

Can it actually be summed up or is it just wishful thinking? Maybe I'm just not finding the threads...

Thank you so much in advance

[Al_The_Man]

One of the first things is to probably Google PID/motion control, there should be enough examples and tutorials to give you the outline of the closed loop manner that servo's are used.
Another source is the online Video tutorials by Dr Jacob Tal on the Galil Motion site.
These are fairly comprehensive & demonstrate by storage scope display the different effects P,I,D has on the system.
Al.

[swdias]

Consider it done...I'll google it now

I really do appreciate the advice

[NC Cams]

use the search engine on CNC zone and look up (servo motor FAQ). TONS of questions are thehre in easy to read laymens tersm. Maris even does an easy to understand "drive a car" explantion of serfo loop goings on.