ChristianAnswers.Net WebBible Encyclopedia
The name “Jew” is derived from the patriarch Judah. At first, it was give to one belonging to the tribe of Judah or to the separate kingdom of Judah (2 Kings 16:6; 25:25; Jeremiah 32:12; 38:19; 40:11; 41:3), in contradistinction from those belonging to the kingdom of the ten tribes, who were called Israelites.
Originally, this people were called Hebrews (Genesis 39:14; 40:15; Exodus 2:7; 3:18; 5:3; 1 Samuel 4:6, 9, etc.), but after the Exile this name fell into disuse. But Paul was styled a Hebrew (2 Corinthians 11:22; Philippians 3:5).
The history of the Jewish nation is interwoven with the history of Israel and with the narratives of the lives of their rulers and chief men. They are now  dispersed over all lands, and to this day remain a separate people, “without a king, and without a prince, and without a sacrifice, and without an image [Revised Version ‘pillar,’ marginal note ‘obelisk’], and without an ephod, and without teraphim” (Hos. 3:4).
There are three names used in the New Testament to designate this people,