Both words aren't clearly defined, and they do overlap. From what I know in fiction supernatural is mostly used for stuff involving gods or cosmic entities and magic and things that beyond human capabilities while paranormal is mostly used for human with powers outside the normal stuff like talking with spirits, mediumship, telepathy, Divination, Levitation and Astral projection.
All magical powers are supernatural. Reality warping, time and space manipulation .... etc all are supernatural.
Humans claim to be able to talk with spirits of the dead or mediumship, claim can levitate or read minds, or be able to see the future (Divination) and other similar powers are paranormal or beyond-normal.