Azure messaging service that enables reliable communication between distributed applications. Like a postal service specifically designed for computer applications to send messages to each other.
An order processing system uses Service Bus to notify inventory and shipping systems when new orders arrive.
Azure Service Bus is a managed enterprise messaging broker (queues and publish/subscribe topics) with features like sessions, dead-lettering, and transactions. AWS typically combines SQS (queues) with SNS (pub/sub fanout). GCP Pub/Sub provides managed pub/sub messaging (with ordering and dead-lettering features) and is often used where topics/subscriptions fit. OCI Queue provides managed queues; for pub/sub-style fanout you may pair it with OCI Streaming or Notifications depending on the pattern.