Определение и Значение "judge a book by its cover"

What is the origin of the idiom "judge a book by its cover" and when to use it?

The idiom "judge a book by its cover" originated from the literal act of forming an opinion or making an assessment about a book based solely on its outer appearance, without considering its content or true value. Figuratively, it signifies the tendency of people to form hasty judgments or make assumptions about someone or something based on superficial or initial impressions. In other words, this phrase is used to emphasize the importance of looking beyond outward appearances and taking the time to understand the true nature or qualities of a person or thing before making a judgment.