Thoughtco summarizes the Zone of Proximal Development here: https://www.thoughtco.com/zone-of-proximal-development-4584842
“The zone of proximal development is the gap between what a student can do independently and what they can potentially do with the help of a “more knowledgeable other.”
Scaffolding is used to provide support from the more knowledgeable other (instructor, parent, etc.), and once the student has learned the new skill, the scaffolding can be removed.”