Difference between Queue and Topic:

Queue	Topic
1) In queues, one message can be consumed by only one client. 2) Queue represent Point-To-Point model. 3) queue is used to send one to one system.  4) In queue the messages are send to FIFO(First in first out) order.	1) In the topics, one message can be consumed by many clients. 2) Topic represent Public and Subscribe  model. 3) topic is used to send more than one system at a time. 4) In Topic  the messages are send to LIFO(Last in first out) order.

Distributed Queue 1) A Distributed Queues are allow you to retrieve a connection to any of the Queues across a cluster by using the Global JNDI name. 2) It seems one of the main pieces of functionality Distributed Queue gives you is load balanced connections across multiple managed servers. 3) The members of the unit are usually distributed across multiple servers within a cluster, with each queue member belonging to a separate JMS server. 4)A distributed queue is a set of physical JMS queue members.

Distributed Topic 1) A distributed topic can be used to create a TopicPublisher and TopicSubscriber. 2) The topic members can be located anywhere but must all be served either by a single WebLogic Server or any number of servers in a cluster. 3) A distributed topic is a set of physical JMS topic members.