excellent reference, I solidified some aspects for me too actually! In addition to defining witnesses, I think it's worth defining "mining".Even though in retrospect it's not an essential term to understand, this concept confused me a lot initially and it came up often . Each time I looked it up the definitions had more concepts that I didn't understand either. I still only understand mining in a very basic and probably incomplete way. And "nodes"...this is a new one for me, how is it different from a witness?