What is a Super Moon?

Supermoons are everywhere lately. We see them talked about on social media by magical and non-magical people alike. Some people are enthralled by them and others don’t really care. But it seems like every full moon this year has been a “Supermoon”. So, I went on a minor mission to figure out what that phrase actually means, if it has any basis in science, or if it’s just a phrase people use when the full moon looks bigger than normal.