What does Amazon SQS provide?

A.
An asynchronous message queue service.

B.
A Simple Query Server, managed directly by Amazon Web Services.

C.
None of these.

D.
A synchronous message queue service.

Explanation:
Amazon SQS stands for Simple Queue Services, and provides a cost-effective way to decouple the components of your
application through an asynchronous message queue service.
http://aws.amazon.com/sqs/