Or does it also include anyone who is trying to acquire new skills regardless of their initial skill level? (e.g. it could be someone who is really skilled in one discipline but wants to acquire new skills in a completely different discipline).
For example, on this White House report they state: "Workers who can benefit from upskilling are both those that are in lowwage jobs as well as those with low skills." https://www.whitehouse.gov/sites/default/files/docs/150423_upskill_report_final_3.pdf