[LAU] Monitor ports - why do I want this?

Hi! Using jack a long time, now. I never activated "monitoring" on my RME HDSP 9652 because I did not know how to make use of it. In qjackctl the big block of additional 26 ports was always in the way… Now, with pipewire, monitoring is activated by default. Surely, I can deactivate it through some configuration I have to investigate further. (Or a neat person here tells me how… :) ) But before I do this I want to make sure not cancelling a handy feature I would have definitely used if I was smart enough… So: What are these "monitor" ports and what can I do with them? And sorry for the newbie question although I'm not a newbie, at all… Greets! Mitsch