Azure Service Bus is a fully managed enterprise integration message broker service offered by Microsoft Azure. It enables communication between different applications and services, both onpremises and in the cloud. Here are some key features and concepts associated with Azure Service Bus: 1. Messaging Patterns: Queue: Provides first-in, first-out (FIFO) messaging between applications. Topic: Allows for publish/subscribe messaging, where a message sent to a topic can be received by multiple subscribers. 2. Message Brokering: Azure Service Bus acts as a mediator for communication between different components of a distributed application. 3. Reliability and Delivery Assurance: Messages sent to queues or topics are stored durably, ensuring reliable message delivery. Supports transactions for atomic send and receive operations. 4. Partitioning: Allows for the partitioning of queues and topics to improve scalability and performance. 5. Dead Lettering: Messages that cannot be delivered after a certain number of attempts are moved to a dead-letter queue for further analysis. 6. Security: Supports integration with Azure Active Directory for authentication. Provides Shared Access Signatures (SAS) for fine-grained access control. 7. Integration with Azure Functions: Azure Service Bus can be used as a trigger or input for Azure Functions, allowing serverless processing of messages. 8. Monitoring and Diagnostics: Integration with Azure Monitor and Azure Log Analytics for monitoring and diagnostics. Metrics and logs help track the health and performance of the Service Bus. 9. SDKs and Language Support: Offers SDKs for various programming languages, including .NET, Java, Python, and more. 10. Compatibility with AMQP and MQTT: Supports industry-standard messaging protocols like Advanced Message Queuing Protocol (AMQP) and Message Queuing Telemetry Transport (MQTT). 11. Auto-Forwarding: Queues and topics can be configured to automatically forward messages to another entity. 12. Geo-Disaster Recovery: Provides the ability to configure a secondary namespace for geo-disaster recovery scenarios. Azure Service Bus is commonly used in scenarios where there is a need for reliable and scalable messaging between decoupled components of an application, especially in a microservices architecture or for connecting on-premises systems with cloud-based applications.