Final answer:
The idiom 'All that glitters is not gold' cautions against judging something solely based on its outward appearance.
Step-by-step explanation:
The statement 'All that glitters is not gold' is an English idiom. It means that not everything that looks attractive or valuable is actually beneficial or genuine. It cautions against judging something solely based on its outward appearance. For example, a person may seem friendly and kind, but they could have ulterior motives or be deceitful.
Learn more about English idioms