What is Azure Service Bus?
Updated Feb 20, 2026
Short answer
Azure Service Bus is a cloud messaging service that helps different applications communicate by sending messages through queues or topics.
Deep explanation
Azure Service Bus acts like a secure middle layer between systems. Instead of one application calling another directly, it sends a message to Service Bus. Another application picks up that message when it is ready.
It supports queues (one sender, one receiver) and topics (one sender, multiple receivers). Messages are stored safely until they are processed, which helps avoid data loss if a system is temporarily down.
Real-world example
An online shopping app sends an order message to Service Bus. The payment service and delivery service both process the order independently without directly depending on each other.
Common mistakes
- - Thinking it is just a database (it is for messaging, not storage).
- - Assuming apps must be online at the same time.
- - Confusing it with direct API calls between services.
Follow-up questions
- What is a queue in Service Bus?
- What is a topic and subscription?
- Why use messaging instead of APIs?