Judaism (Hebrew: יַהֲדוּת; from the Greek Ioudaïsmos, the distinctive charactaristics of the Judean eáqnov; Judean from the Hebrew יהודה, Judah) is the religion of the Jewish people, based on principles and ethics embodied in the Hebrew Bible (Tanakh), as further explored and explained in the Talmud. In 2007, the world Jewish population was estimated at 13.2 million people—41 percent in Israel and 59 in the diaspora.

According to Jewish tradition, the history of Judaism begins with the Covenant between God and Abraham (ca. 2000 BCE), the patriarch and progenitor of the Jewish people. Judaism is among the oldest religious traditions still in practice today. It is believed that other religions, such as Christianity, Islam and the Bahá'í Faith, were derived from Judaism. Christians, however, maintain that Judaism was a preparation for the Gospels, as revealed by Jesus, while Muslims claim that Islam is a return to the pure message of Abraham.

Judaism differs from many religions in that in modern times, central authority is not vested in any single person or group, but in sacred texts, traditions, and learned Rabbis who interpret those texts and laws. Throughout the ages, Judaism has clung to a number of religious principles, the most important of which is the belief in a single, omniscient, omnipotent, benevolent, transcendent God, who created the universe and continues to govern it. According to traditional Jewish belief, the God who created the world established a covenant with the Israelites, and revealed his laws and commandments to Moses on Mount Sinai in the form of both the Written and Oral Torah, and the Jewish people are the descendants of the Israelites. The traditional practice of Judaism revolves around study and the observance of God's laws and commandments as written in the Torah and expounded in the Talmud.