Explain the concept of a Renderless Component in React

Question

The redrive policy specifies the source queue, the dead-letter queue, and the circumstances in which Amazon SQS moves messages from the former to the latter if the consumer of the source queue fails to process a message a predetermined number of times, according to a document I'm reading about the deadletter queue and re-drive policy.

But even the document made many references to "message process failed," so I'm not sure how sqs recognises a message processing failure (and thus triggers re-drive or move to the dead letter queue.)

I believe that consumer apps use the receiveMessage function to retrieve messages from SQS and subsequently process them. ReceivingMessage does not receive the processing function as a lambda. How does SQS understand that message then?