jms-listener vs jms-source

[diippi]

I need to be listening to a queue and I see that I can use either jms-source or jms-listener to do the same. Which should I be using ?
What does jms-source offers above jms-listener and vice-versa ?

Also, I noticed that when I used jms-source to read the messages from the queue, the queue still retained the message (did not flush).
While in jms-listener the queue empties as the message is read/processed . Is there any particular implementation detail that Im missing here ?