比例 (bǐ lì) means 'ratio' or 'proportion' — the quantitative relationship between two or more quantities, often expressed as a fraction, decimal, or with a colon (e.g., 3:2). The character 比 (bǐ) means 'to compare' or 'to match', while 例 (lì) means 'example', 'case', or 'instance'; together, they convey the idea of comparing things by standardized cases or relative measures. This word is widely used in mathematics, statistics, design, economics, and everyday comparisons — for instance, when describing the ratio of ingredients in a recipe, screen resolution (16:9), or demographic data.

Unlike colloquial expressions like ‘几分之几’ (a fraction of), 比例 carries a formal, precise tone and frequently appears in written reports, charts, academic contexts, and technical instructions. It can function as the subject, object, or complement in a sentence, and is often modified by measure words like ‘个’ (e.g., 一个比例) or quantifiers like ‘一定’ (a certain ratio) or ‘适当’ (an appropriate proportion).