Amazon SQS is simply a queuing service. It is a producer-driven system in which, the SQS sends the message to a consumer and that is it. The messaging system cannot be driven by the consumer. Amazon MQ (which runs on ActiveMQ), is a message broker which means that, the messaging system is consumer driven. Also, MQ has the scope of variable retention period which can be upto a few days. You can keep track of the message that is received and call back on that from the broker at a later time (as long as that is within the retention period). Once all of this is coded into your consumer, then Amazon MQ can be used for pulling back messages from the broker on demand.