MOQT has a hierarchical data model, comprised of tracks which contain groups, and groups that contain objects. Inside of a group, the objects can be organized into subgroups.
To give an example of how an application might use this data model, consider an application sending high and low resolution video using a codec with temporal scalability. Each resolution is sent as a separate track to allow the subscriber to pick the appropriate resolution given the display environment and available bandwidth. Each "group of pictures" in a video is sent as a group because the first frame is needed to decode later frames. This allows the client to join at the logical points where they can get the information to start decoding the media. The temporal layers are sent as separate sub groups to allow the priority mechanism to favour the base layer when there is not enough bandwidth to send both the base and enhancement layers. Each frame of video on a given layer is sent as a single object.