高效 (gāo xiào) is an adjective meaning 'high-efficiency' or 'highly efficient'. It combines two characters: 高 (gāo), meaning 'high' or 'elevated', and 效 (xiào), meaning 'effect', 'efficacy', or 'result'. Together, they describe something that achieves maximum output or desired results with minimal waste of time, energy, or resources. The term emphasizes effectiveness *and* economy — not just speed, but optimal performance.

This word is widely used in professional, academic, and everyday contexts — for example, describing work methods, study techniques, machines, software, or personal habits. It often appears in compound nouns like 高效学习 (gāo xiào xuéxí, 'efficient studying') or 高效沟通 (gāo xiào gōutōng, 'effective communication'). While it carries a positive, modern connotation, it’s neutral in register — appropriate in both formal reports and casual conversation when praising practicality and smart resource use.