Java Message Service (JMS) is a messaging standard that allows different software applications to communicate with each other in a reliable and asynchronous manner. It enables the exchange of messages between clients and servers, facilitating communication in distributed systems. JMS is commonly used in enterprise applications to ensure that messages are delivered even if the receiving application is temporarily unavailable. JMS supports two messaging models: point-to-point and publish-subscribe. In the point-to-point model, messages are sent from one sender to one receiver, while in the publish-subscribe model, messages are sent from one sender to multiple subscribers. This flexibility makes JMS a popular choice for building scalable and robust applications.