What is QiGong?

QiGong was in fact derived from Nei Gong

NeiGong was traditionally only taught to the highest level monks, as it required much prior training and knowledge. For example WuJi and Luohan Ruyi, the 2 core arts in Shaolin NeiGong, each have 36 and 108 forms respectively (a form is a sequence of many flowing, precise movements, involving arms, body and legs). For centuries, it was kept as a secretive art and not taught to layman outside of Shaolin or Wudang.

As the health benefits became known, about two centuries ago, some of the monks began to teach it outside the monastery. In order for laypersons to learn, it was simplified and became renamed as QiGong. As QiGong became popular, it branched into many versions, even with a few created in the West, without any heritage to the ancient sources.