对比 (duì bǐ) is a noun meaning 'comparison' — the act of examining two or more things side by side to identify similarities and differences. The character 对 (duì) means 'opposite', 'facing', or 'mutual', while 比 (bǐ) means 'to compare' or 'to measure against'. Together, they form a compound that emphasizes a structured, often analytical, side-by-side evaluation. It’s commonly used in academic writing, data analysis, product reviews, and everyday reasoning — for instance, when weighing pros and cons or evaluating changes over time.

This word functions as a noun and typically appears after verbs like 进行 (jìnxíng, 'to conduct'), 做 (zuò, 'to do'), or 有 (yǒu, 'to have'), or as the subject/object of a sentence. Unlike the verb 比 (bǐ), which directly compares two items (e.g., A 比 B 好), 对比 requires an explicit object or context and carries a more formal, reflective tone.