常识 (cháng shí) literally means 'common knowledge' — 常 (cháng) means 'ordinary' or 'frequent', and 识 (shí) means 'knowledge' or 'understanding'. Together, they refer to basic, widely accepted practical knowledge that most people in a society are expected to possess — not specialized expertise, but everyday reasoning about safety, health, social norms, or cause-and-effect (e.g., fire is hot, water puts out flames, washing hands prevents illness). It’s the kind of understanding that helps people make sound judgments without formal instruction.

This word often appears in educational, journalistic, or advisory contexts — for example, in public service announcements, school curricula, or discussions about critical thinking. While it overlaps with 'common sense' in English, 常识 places more emphasis on shared factual awareness than intuitive judgment. It can be used abstractly ('lack of common sense') or concretely ('teaching children basic safety常识').