A teaser is something that is designed to arouse interest or excitement, typically by being intriguing, mysterious, or provocative. It can refer to a promotional item such as an advertisement or trailer that offers just enough information to pique someone's curiosity and encourage them to seek out more details. In this context, the teaser is used to generate interest in a product, event, or piece of content by giving people a taste of what it has to offer without revealing too much.