Key Terms in This Chapter

This section explains key technical terms used in this chapter, with an emphasis on clarifying the relationships between these terms how they are used in the Java Enterprise System context.

adoption scenario

An overall reason for deploying Java Enterprise System software, characterizing the software system you start with and the goal you are trying to achieve. There are four basic Java Enterprise System adoption scenarios: new system, replacement, extension, and upgrade.

component

A unit of software logic from which distributed applications are built. A component can be one of the system components included in Java Enterprise System or an application component that is custom developed. An application component usually conforms to a distributed component model (such as CORBA or the J2EE^TM platform) and performs some specific computing function. These components, singly or combined, provide business services and can be encapsulated as web services.

distributed enterprise application

An application whose logic spans a network or Internet environment (the distributed aspect) and whose scope and scale meet the needs of a production environment or service provider (the enterprise aspect).

end user

A person who uses a distributed application, often through a graphical user interface, such as an Internet browser or mobile device GUI. The number of concurrent end users supported by an application is an important determinant of the deployment architecture of the application.

service

A software function performed for one or more clients. This function might be at a very low level, such as a memory management, or at a high level, such as a credit check business service. A high-level service can consist of a family of individual services. Services can be local (available to local clients) or distributed (available to remote clients).

service quality component

One of a number of kinds of system components included in Java Enterprise System. Components enhance the availability, security, scalability, serviceability and other qualities of system serice components and distributed application components..

shared component

One of a number of kinds of system components included in Java Enterprise System. Shared components, usually libraries, provide local services to other system components. By contrast, a system service component provides distributed infrastructure services to other system components (or to application components).

system component

Any software package or set of packages included in the Java Enterprise System and installed by the Java Enterprise System installer. There are several kinds of system components: system service components that provide distributed infrastructure services, service quality components which support the system services components by providing access and administrative services, and shared components that provide local services to other system components.

system service

One or more distributed services that define the unique functionality provided by Java Enterprise System. System services normally require the support of a number of service quality components, a number of shared components, or some of both.

system service component

One of a number of kinds of system components included in Java Enterprise System. System services components provide the main Java Enterprise System infrastructure services: portal services, communication and collaboration services, identity and security services, web and application services, and availability services.