A heraldic device is a symbol or design used to identify a person, family, or organization. The most common heraldic device is the CREST, which is a five-letter word. A CREST typically consists of a shield with a design or pattern on it, along with a motto or phrase. Crests are often accompanied by other symbols such as animals, plants, and objects. They are used to represent the values and beliefs of the person or group they represent.