Looping or iterations are new to V4 and allow the output of some process within the filter to be fed back as input with a control about how many times through the loop the image is (re)sent.
One of my goals is to have the time to do more things like FF work. I am blessed with great real life work along with a number of very welcome community commitments, though taken together they mean that there are a number of things I don't get to do as much of as I'd like.
I did choose my forum title honestly