Java 2 Platform, Enterprise Edition.

Any deployable unit of J2EE functionality. This can be a single J2EE module or a group of modules packaged into an EAR file along with a J2EE application deployment descriptor. J2EE applications are typically engineered to be distributed across multiple computing tiers.

A self-contained functional software unit supported by a container and configurable at deployment time. The J2EE specification defines the following J2EE components:

Application clients and applets are components that run on the client.

Java servlet and JavaServer Pages (JSP) technology components are Web components that run on the server.

Enterprise JavaBeans (EJB) components (enterprise beans) are business components that run on the server.

J2EE components are written in the Java programming language and are compiled in the same way as any program in the language. The difference between J2EE components and standard Java classes is that J2EE components are assembled into a J2EE application, verified to be well formed and in compliance with the J2EE specification, and deployed to production, where they are run and managed by the J2EE server or client container.

A software unit that consists of one or more J2EE components of the same container type and one deployment descriptor of that type. There are four types of modules: EJB, Web, application client, and resource adapter. Modules can be deployed as stand-alone units or can be assembled into a J2EE application.

An implementation that conforms to the J2EE platform specification.

A vendor that supplies a J2EE product.

The runtime portion of a J2EE product. A J2EE server provides EJB or Web containers or both.