This recipe showed you how to create disaster recovery backups, restore your application and its data back from an S3 target, and how to create scheduled backup jobs on Kubernetes.
In the Backing up an application recipe, in Step 4, when you run velero backup create myapp-backup --selector app=app2backup, the Velero client calls the Kubernetes API server and creates a backup object.
You can get a list of Custom Resource Definitions (CRDs) that have been created by Velero by running the kubectl get crds |grep velero command.
Velero's BackupController watches for a new object and when detected, it performs standard validation and processes the backup. Velero's BackupController collects the information to back up by asking resources from the API server. Then, it makes a call to the default storage provider and uploads the backup files.