This post is part five of a series on building an app with spatialization features using Daily's real-time video and audio APIs. The introduction reviews previous posts on setting up the 2D world and managing users' video and audio tracks based on proximity to each other in a traversal space. The main topic of this post is creating different kinds of interactive elements for users to join different zones or broadcast to everyone else in the world. Zones are defined as areas with distinct behaviors, including global traversal zone, broadcast focus zone, and isolated focus zone. Users can interact with these zones by entering or leaving them, which updates their video and audio tracks accordingly. The post covers the implementation of broadcast zones and desk zones, including the unique behaviors of each type. It also discusses how users' zone updates are handled when another user joins or leaves a zone, and how this logic is structured for every tick of the world. Overall, this post provides an in-depth look at how focus zones interact with users and facilitate spatialization features in the app.