In the original comic books, this is a supernatural family (specifically members of a race of witches) that lives in Riverdale of the Archie Comics universe, though they did not have the surname Spellman for the first thirty years. In the Little Archie continuity, Sabrina has lived in Riverdale since she was a small child. They tried to avoid drawing attention to themselves but also did not fear attention, part of the "live and let live" theme that pervades the Archie Comics universe.
In the 1990s live-action TV series and now sometimes in the comic books, this is a supernatural family of witches that live in a town called Greendale, located near Riverdale, and try to live normal lives. In this continuity, Sabrina Spellman is half witch half mortal (human) and still learning how to control her magical powers.
In both cases, Sabrina lives with her two aunts instead of her parents. In the comic books, her Aunt Zelda is aggressive and powerful while her Aunt Hilda is shy and less talented; in the live-action TV series, Zelda is a sophisticated and smart witch while Hilda is not quite so intelligent. Sabrina's Cousin Ambrose is a warlock who has a weakness for trends and a certain pomposity but remains devoted to his cousin Sabrina.