Explain Enterprise Java Beans (EJB)

Enterprise Java Beans (EJB) is a server-side software component that encapsulates business logic of an application. EJB is part of the Java EE (Enterprise Edition) specification and helps developers create robust and scalable applications by providing various built-in features such as transaction management, security, and concurrency control. EJB allows for the development of distributed applications running on multiple machines and provides simplify distributed computing in a reliable way.

With EJB, business logic can be easily separated from the presentation layer. There are different types of EJBs including Session Beans, Message-Driven Beans, and Entity Beans that serve various purposes such as handling database transactions and processing messages from external systems.

The EJB container manages the lifecycle of EJB components, providing the necessary resources that applications can leverage, thus allowing developers to focus on writing the business logic without needing to worry about the underlying infrastructure.