I was wondering why the hell we are seeing this supermoon phenomenon today. i did had this basic idea that moon’s path will be closer today to the earth and i assumed that moon might revolve around an elliptical orbit around earth, and not circular.
Just to confirm i did some “Googling” and found the same information. However few terms just reminded me of my school time. In school we did read about apogge and perigee and sadly i didnt remember these, but when i just read these terms i was able to recall everything 
Moon revolves around the Earth in an elliptical orbit. The fathest point on the path is called apogee and the closest perigee. So today Moon will reach perigee point and thus will be closest to earth and will look bigger.
I didn’t want to share gyan here, but it was just that I felt somewhat nostalgic thinking about my school days
By the way there is a video posted by NASA explaining the supermoon funda:
