The Java Message Service(JMS) API for accessing enterprise
messaging systems. It is part of the Java 2
platform,Enterprise Edition(J2EE). The Java Message Service
makes it easy to write business applications that
asynchronously send and receive critical business data and
events.
   The java Message Service defines a common enterprise
messaging API that is designed to be easily and efficiently
supported by a wide range of enterprise messaging products.
   The java Message Service supports both message queing and
publish-subscribe styles of messaging.