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.

application component

A custom-developed software component that performs some specific computing function, providing business services to end users or to other application components. An application component usually conforms to a distributed component model (such as CORBA and the J2EE^TM platform). These components, singly or combined, can be encapsulated as web services.

architecture

A design that shows the logical and physical building blocks of a distributed application (or some other software system) and their relationships to one another. In the case of a distributed enterprise application, the architectural design generally includes both the application’s logical architecture and deployment architecture

business service

An application component or component assembly that performs business logic on behalf of multiple clients (and is therefore a multi-threaded process). A business service can also be an assembly of distributed components encapsulated as a web service, or it can be a standalone server.

client

Software that requests software services. (Note: this is not a person—see end user.) A client can be a service that requests another service, or a GUI component accessed by an end user.

deployment architecture

A high-level design that depicts the mapping of a logical architecture to a physical computing environment. The physical environment includes the computers in an intranet or Internet environment, the network links between them, and any other physical devices needed to support the software.

logical architecture

A design that depicts the logical building blocks of a distributed application and the relationships (or interfaces) between these building blocks. The logical architecture includes both the distributed application components and the infrastructure services components needed to support them.

server

A multi-threaded software process (as distinguished from a hardware server) that provides a distributed service or cohesive set of services for clients that access the service by way of an external interface.

web service

A service that conforms to standardized Internet protocols for accessibility, service encapsulation, and discovery. The standards include the SOAP (Simple Object Access Protocol) messaging protocol, the WSDL (Web Service definition Language) interface definition, and the UDDI (Universal Discovery, Description, and Integration) registry standard.