An application group is a set of data that you want to protect. For Kubernetes, the data is the Kubernetes applications, namespaces, namespaced objects, non-namespaced objects, and persistent volume data that you want to protect.
When you add a cluster that you want to protect to Commvault, that process includes creating the first application group for the cluster. The first application group that you create for a cluster is the default application group, regardless of what the application group is named.
After you add a cluster and create the default application group, you can create additional application groups for objects/resources in the cluster that have different backup requirements. Additional application groups can be either of the following: