What is the Difference Between a JMS Topic and a JMS Queue
Question: What is the Difference Between a JMS Topic and a JMS Queue?
In JMS Topic implements publish and subscribe semantics. When you publish a message it goes to all the subscribers who are interested – so zero to many subscribers will receive a copy of the message. Only subscribers who had an active subscription at the time the broker receives the message will get a copy of the message.
A JMS Queue implements load balancer semantics. A single message will be received by exactly one consumer. If there are no consumers available at the time the message is sent it will be kept until a consumer is available that can process the message. If a consumer receives a message and does not acknowledge it before closing then the message will be redelivered to another consumer. A queue can have many consumers with messages load balanced across the available consumers. (E learning)