Queues are a standard part of JMS, please consult the JMS 1.1 specification for full details.
A QueueBrowser is used to look at messages on the queue without removing them. It can scan the entire content of a queue or only messages matching a message selector.
The example will send 2 messages on a queue, use a QueueBrowser to browse the queue (looking at the message without removing them) and finally consume the 2 messages.