The service bus is used to provide interaction between services or applications run in the cloud with other services or applications. The service bus trigger is used to give the response to messages which come from the service bus queue or topic.

We have two types of service bus triggers:

• Service bus queue trigger: A queue is basically for first-in-first-out messages. When a message comes from the service bus, the service bus queue trigger gets fired and the Azure Function is called. In the Azure Function, we can process the message and then deliver it.
• Service bus topic trigger: The topic is useful for scaling to very large numbers of recipients.