GA4 Audiences are a feature in Google Analytics 4 that allows users to segment their data further. They provide many more options than the previous segments in Universal Analytics and are built from criteria set by the user. Audiences can also be time-based, meaning users can define criteria for specific periods of time, such as how many people watched three or more videos in a 30-day span. In addition to being useful for reporting on ad campaigns, Audiences can be used as reports within the GA4 interface or exported through the GA4 API for use in other tools. To create an Audience, users can go into Admin in GA4, click on “Audiences,” and then “Create an Audience.” There are three ways to create Audiences: dimensions, metrics, and events, each with their own criteria. It is important to note that Audiences do not backfill, so users should create them as soon as possible to avoid missing out on important data. Audiences can be static or dynamic, depending on whether the data being collected is happening now or happened in the past. Finally, users can use triggers for Audiences to create an event when someone becomes a member of an Audience, which is useful for tracking customer behavior. Overall, Audiences are a powerful tool that can provide further insights into a company’s marketing efforts beyond just ad campaigns.