A 'verification code' is a short, temporary string of letters, numbers, or symbols used to confirm a user's identity or action during online processes. The word combines three characters: 验 (yàn, 'to test or verify'), 证 (zhèng, 'evidence or proof'), and 码 (mǎ, 'code or cipher'). Together, they literally mean 'verification evidence code' — emphasizing its role as a security measure that proves the user is human or authorized.

This term appears frequently in digital contexts: when registering for accounts, logging in, resetting passwords, or completing payments. Verification codes are often sent via SMS, email, or generated within authentication apps. They typically expire quickly (e.g., within 5–10 minutes) to prevent misuse. While sometimes called 'captcha', 验证码 specifically refers to one-time codes sent directly to users, not image-based challenges.