What is systems change? The start of aggregating information (a stub)

In the Facebook COVID-19 Resources (Systems Community) (via Facebook https://www.facebook.com/groups/SCA.COVID19/permalink/553322955370095/), Rob Young asks:

I’ve been trying to understand what the movement/ field of ‘Systems change’ is.
As a ‘movement’, it seems to have emerged fairly recently, and has been taken up by large, well funded, politically active groups, whose agenda was not clear to me.
(apologies for any ignorance of mine)
This Harvard Business Review article/ case study has helped me form a (personal, initial) opinion that it is a valid systems approach, and potentially, an important one.
(I don’t yet have an opinion on the political/ agenda aspects. – compare with how ideas like ‘climate’, ‘ecology’, ‘woke’ etc get mis-appropriated by hidden agendas).
My positive take on ‘systems change’ is that: it is proactive, design and implementation of real world, system based change; It is one of the fields of *systems practice*; It is like a softer version of systems engineering.
[Why Social Ventures Need Systems Thinking – Journal article – Harvard Business Review (Vanessa Kirsch , Jim Bildner and Jeff Walker) – Systems Change – 25-Jul-2016]:
(Harvard Business Review seems to be behind a registration wall, but does offer viewing of 2 Free articles, without registration]
My immediate responses:
Related events this week:

Otherwise, many links:

https://stream.syscoi.com/?s=%22systems+change%22

It is a large and multiply defined field (especially if you include systems changes, systems innovation, systems weaving, systems convening, systems building etc). I have been building a  folder of all key documents related to ‘place-based systems change’ which is edging towards 400 items…