Daily Active Users (DAU) refers to the number of unique users who engage with a specific application or platform within a single day. This metric is crucial for businesses and developers as it helps them understand user engagement and the overall health of their product. A higher DAU indicates that more people are finding value in the service, which can lead to increased revenue and growth opportunities. Tracking DAU allows companies to identify trends and patterns in user behavior. For instance, if a social media platform like Facebook sees a drop in DAU, it may need to investigate potential issues or improve features to retain users. Regular monitoring of DAU can inform strategic decisions and enhance user experience.