There was yet another supermoon earlier this week. Lately these occurrences have been widely marketed around the media giving them each some obscure unique name as if mere super- preposition wouldn't be enough.
Supermoon isn't a scientific term, but the even itself has some scientific significance. The so called supermoon happens when the full moon and perigree (that is, when the moon is closest to earth on it's elliptical orbit) happens close enough to each other. Between perigree and apogee (opposite of perigree) the distance between moon and earth varies up to around 45 000 km. This can make the moon actually appear close to 14 percent bigger in the sky.
Another thing related to the moon size is the moon illusion. While the moon is close to the horizon it appears bigger than when it's above us up in the sky. This, however, is a pure illusion. It's just our minds doing tricks on us.
Combining these two with the amplified expectations from the media can make our minds to outright lie to us making us believe that these supermoons, especially when observed close to the horizon are something spectacular and almost out of this world.
Despite all this, there is nothing stopping you from enjoying such a spectacular view when the time is right and the sky is clear.