What is an event hub / event broker?
An event hub / event broker is a distributed event streaming platform for high-performance data pipelines, streaming analytics, data integration, and mission-critical applications. It is an essential component in an Event-Driven Architecture.
An event hub does not allow you to define business logic on the cluster, which means it is a purely technical component and not the same as an ESB. This eliminates the need for a separate ESB team. By using an event hub business logic is always handled in the component that is responsible of the business domain, which has obvious benefits for maintainability and scalability.