Accurate 1. Conforming exactly to fact; errorless.
2. Deviating only slightly or within acceptable limits from a standard.
3. Capable of providing a correct reading or measurement.
4. Acting or performing with care and precision; meticulous.
Digital servos can be programmed for speed, torque, length of throw and centering and a few other things. That's what I'm told by the guys using them at the flying field. There's a computer program and a USB cable. You program them for what you want and then feed that info back to a memory chip in the servo through the USB.
Also, if I'm correct, not all receivers can deal with digital servos.