How to use simple services?

When adding a receive step I noticed that there is an implementation option of ‘Simple Service (For Synchronous Reply)’. Could someone please explain how this simple service works and what it is used for?

I believe that this functionality may be beneficial to a project I am working on.

Synchronous publishRequestAndWait gives less performance than the asynchronous one.

From Developer manual:

“If your service that publishes multiple requests and retrieves multiple replies, consider making the requests asynchronous. You can construct the service to publish all the requests first and then collect the replies. This approach can be more efficient than publishing a request, waiting for a reply, and then publishing the next request”.