Curious about Wand Mask algorithm

I'm just interested what's the operation behind the wand tool Is it something similar to this Zone System?
https://en.wikipedia.org/wiki/Zone_System
No other keyer gives that smooth noise free selections - that's what I love about the Wand Mask particularly the most.
You know just highening up the topic about it to insist on it's further development...
https://en.wikipedia.org/wiki/Zone_System
No other keyer gives that smooth noise free selections - that's what I love about the Wand Mask particularly the most.
You know just highening up the topic about it to insist on it's further development...