A sunroof or moonroof is a glass window section of roof that allows drivers and passengers to look through the roof without removing it or having a permanent hole in the roof. It often has the option of being moved, either by hand or automatically, so that the glass becomes an opening.
Diagnosing & Repairing a Sunroof Leak by Cars Simplified
Having a hole in the roof of your car makes it quite prone to leaks, and when that happens the source of the leak needs to be traced so repair attempts work. As shown in the video, following the water up to the source will help you discover the problem.