[Grafana 7] unknow function

I was working on a dashboard and trying to copy/paste some panel directly in the JSON model on another dahsboard.
So i did it and i visualise sometihng i’ve never seen and I don’t know what it’s for or how it works.

Can someone help me to know what is it and how it works ?

Where did you copy it from

From another JSON model in grafana,
i copied the" panels" part from JSON of my first dashboard and paste it in JSON model of my second dashboard