An application group is a collection of client applications that connect to an Event Hubs namespace sharing a unique identifying condition such as the security context - shared access policy or Azure Active Directory (Azure AD) application ID. Azure Event Hubs enables you to define resource access policies such as throttling policies for a given application group and controls event streaming (publishing or consuming) between client applications and Event Hubs. Reference: https://docs.microsoft.com/en-us/azure/event-hubs/event-hubs-features.