Service Bus queues are part of a broader Azure messaging infrastructure that supports queuing as well as publish/subscribe, Web service remoting, and integration patterns
Microsoft Azure Service Bus supports a set of cloud-based, message-oriented-middleware technologies including reliable message queuing and durable publish/subscribe messaging. These “brokered” messaging capabilities can be thought of as asynchronous, or decoupled messaging features that support publish-subscribe, temporal decoupling, and load balancing scenarios using the Service Bus messaging fabric. Decoupled communication has many advantages; for example, clients and servers can connect as needed and perform their operations in an asynchronous fashion.
https://msdn.microsoft.com/en-us/library/azure/hh367516.aspx
