Samaria is the hill country north of Judea, the heartland of the northern kingdom of Israel and the homeland of the Samaritans, and the whole of its religious significance turns on a single disagreement.
The Samaritans hold that the place God chose for worship is Mount Gerizim, above Nablus, and not Jerusalem. Their Torah, which differs from the Jewish text in a number of places, makes that explicit, and they read Jewish scripture and Jewish institutions as a later departure from the original arrangement rather than the reverse. They accept only the five books of the Torah, not the prophets or the writings, and they trace their priesthood to Aaron through a line they hold to be unbroken.
Jewish sources tell the story the other way, as the descent of a population settled in the north by Assyria after 722 BCE, worshipping the God of Israel alongside other gods. Modern scholarship generally treats the Samaritans as a genuinely Israelite community that separated from the Judean one gradually, over centuries, rather than as either a survival or an import, with the destruction of the Gerizim temple by a Hasmonean ruler in the second century BCE as a decisive moment.
Reinhard Pummer's survey of the evidence sets out how much of the traditional Jewish and Christian account of Samaritan origins reflects polemic rather than history, and how the group's own claims have fared under examination.