Beit Shammai refers to a prominent school of thought in ancient Judaism that was founded by the sage Shammai during the late Second Temple period. This school is known for its more stringent interpretations of Jewish law and often stood in opposition to Beit Hillel, the competing school that offered more lenient interpretations. Beit Shammai's debates and rulings have greatly influenced Jewish legal discourse and continue to be referenced in discussions about halakha (Jewish law).