Service Bus Topics & Subscriptions

Senders send messages to a topic in the same way that they send messages to a queue, but it varies on a slight factor where 'Topics' can have multiple, independent 'Subscriptions'. Subscriptions are durable by default but can be configured to expire and then be automatically deleted.

We can define rules on a subscription. A subscription rule has a filter to define a condition for the message to be copied into the subscription and an optional action that can modify message metadata.