What is green computing in non-technical term?

The camera still is bad even with the new iphone xr and especially in low light it is even worst because you can see the pixels more if its in low light. if all you apple customers want apple to fix this then lets fill there feedback with complaints about the

The more powerful, 60 volt cables and the main power shut-off on an hev are both colored orange.

What are "open-loop" and "closed-loop" systems