Most people assume the Jewish people are the sole remaining descendants of the ancient nation of Israel. This assumption, however, is incorrect.
Technically the Jews are descendants of two of the Israelite tribes: Judah and Benjamin, plus a considerable part of a third, the priestly tribe of Levi.
Unknown to most, 10 other tribes in ancient Israel were never called Jews. These northern tribes were historically distinct and politically separate from the Jews, their brothers to the south who formed the kingdom of Judah, from which the term Jew was derived.
The northern coalition of tribes, the kingdom or house of Israel, had already become an independent nation, separate from the house of Judah, by the time the word Jew first appears in the biblical narrative. In fact, the first time the term appears in the King James Version of the Bible, Israel was at war with the Jews (2 Kings 16:5-6 2 Kings 16:5-6  Then Rezin king of Syria and Pekah son of Remaliah king of Israel came up to Jerusalem to war: and they besieged Ahaz, but could not overcome him.
 At that time Rezin king of Syria recovered Elath to Syria, and drove the Jews from Elath: and the Syrians came to Elath, and dwelled there to this day.
American King James Version×).
Are all Israelites Jews? No. Jews—the citizens and descendants of the kingdom of Judah—are indeed Israelites, but not all Israelites are Jews. Since all 12 tribes, including Jews, are descendants of their father Israel (Jacob), we can apply the term Israelite to all of the tribes. The term Jew, however, is accurate only for the tribes that comprised the kingdom of Judah and for their descendants.