The term "poster boy" is a figurative expression that refers to an individual who represents or personifies something, often in a positive way. The phrase originated from the use of posters as a means of advertising and propaganda during the 19th century. A poster would feature an image of a young boy, typically depicted as strong, healthy, and happy, to promote various products or causes such as enlisting in the army, buying war bonds, or supporting charities. Over time, the phrase "poster boy" has evolved into a more general term used to describe someone who is an exemplary representative of something, often through their actions or achievements.