dos,
there are two differences:
- queued messages are not overwritten; they are stored until the recipient unqueues them. The sender can queue 10 messages in a row and seconds later the recipient can unqueue all 10 of them. Notifications are overwritten. The recipient can retrieve only the last message notified.
- Notifications can be sent to many recipients. All recipients waiting for a notification will receive it when it is sent. Queued messages are unqueued once only by one recipient.
Then to send messages to a recipient from many sources, use a queue. To broadcast a message to many recipient from one or mant sources, use notifiers.
