Azure Service Bus is a generic, cloud-based messaging system for connecting just about anything—applications, services, and devices—wherever they are. Connect apps running on Azure, on-premises systems, or both. You can even use Service Bus to connect household appliances, sensors, and other devices like tablets or phones to a central application or to each other.
Asynchronous messaging patterns are the architectural cornerstone of reliable and scalable applications. Integrating cloud resources like Azure SQL Database, Storage, and Web Apps for App Service, with Service Bus messaging ensures smooth operation under heavy and variable load with the durability to survive intermittent failures.
Queues offer simple first in, first out guaranteed message delivery and support a range of standard protocols (REST, AMQP, WS*) and APIs. Topics deliver messages to multiple subscriptions and fan out message delivery at scale to downstream systems.
The Service Bus relay service solves the challenges of communicating between on-premises applications and the outside world by allowing on-premises web services to project public endpoints. Systems can then access these web services, which continue to run on-premises from anywhere on the planet.