The process whereby software is installed into an operational environment.

An XML file provided with each module and J2EE application that describes how they should be deployed. The deployment

descriptor directs a deployment tool to deploy a module or application with specific container options and describes specific

configuration requirements that a deployer must resolve.

A JMS administered object that encapsulates the identity of a JMS queue or topic. See point-to-point messaging system,

publish/subscribe messaging system.

An authentication mechanism in which a Web application authenticates itself to a Web server by sending the server a message

digest along with its HTTP request message. The digest is computed by employing a one-way hash algorithm to a concatenation

of the HTTP request message and the client's password. The digest is typically much smaller than the HTTP request and doesn't

contain the password.

An application made up of distinct components running in separate runtime environments, usually on different platforms

connected via a network. Typical distributed applications are two-tier (client-server), three-tier

(client-middleware-server), and multitier (client-multiple middleware-multiple servers).

In general, an XML structure in which one or more elements contains text intermixed with subelements. See also data.

An API for accessing and manipulating XML documents as tree structures. DOM provides platform-neutral, language-neutral

interfaces that enables programs and scripts to dynamically access and modify content and structure in XML documents.

The top-level directory of a WAR. The document root is where JSP pages, client-side classes and archives, and static Web

resources are stored.

Document type definition. An optional part of the XML document prolog, as specified by the XML standard. The DTD specifies

constraints on the valid tags and tag sequences that can be in the document. The DTD has a number of shortcomings, however,

and this has led to various schema proposals. For example, the DTD entry says that the XML

element called username contains parsed character data-that is, text alone, with no other structural elements under it. The

DTD includes both the local subset, defined in the current file, and the external subset, which consists of the definitions

contained in external DTD files that are referenced in the local subset using a parameter entity.

In a JMS publish/subscribe messaging system, a subscription that continues to exist whether or not there is a current active

subscriber object. If there is no active subscriber, the JMS provider retains the subscription's messages until they are

received by the subscription or until they expire.