勤劳 (qín láo) is a formal, written adjective meaning 'hardworking, industrious' — it describes a person's enduring work ethic or a people's character, often used in praise. It is more formal and broader than 勤奋 (qín fèn), which focuses on sustained effort in study or work, and unlike 用功 (yòng gōng), which is limited to studying, 勤劳 applies to any labor or daily life.