- A middle ware from IBM

- It has runtime managers such as Queue Managers and Queues

- Queue is an object which holds messages of various formats – XML/text/byte

- Queue manger maintains and manages objects like Queues, channels

- Various listener applications listen to these queues for grabbing the messages, followed by processing these messages

- Java Messaging Service is one of the standards provided by JEE specification for asynchronous messaging

- The queues can be defined in JEE container and send messages on these queues

- Message Driven Bean can be configured for listening the JMS queues

- When a message is on the JMS queue, the corresponding MDB’s onMessage() method is invoked and the message processing can be done