How do queues work?

As shown in Figure 12.2, SQS works on the put-get-delete paradigm:

Figure 12.2: Working of SQS

The put-get-delete paradigm works in the following way:

1. The publishing application pushes a message, M, into the queue.
2. The consuming application pulls the message, M, from the queue and processes it.
3. The consuming application confirms to the SQS queue that processing on the message is completed and deletes this message from the SQS queue.