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Glossary

anchor A part of a hypertext document that is either the source or destination of a hypertext link. A link might extend from an anchor to another document, or from another document to an anchor. When anchors are the starting points of these links, they are typically highlighted or otherwise identified in the hypertext browser as hotspots.

API (Java) Application Programming Interface The set of Java packages and classes—included in the Java Developers Kit (JDK)—that programmers use to create applets.

ASCII American Standard Code for Information Interchange. A 7-bit character code that can represent 128 characters, some of which are control characters used for communications control and are not printable.

applet A Java program that can be included in an HTML page with the APPLET element and observed in a Java-enabled browser.

application (Java) A computer program—written in Java—that executes independently of a Java-enabled browser through the Java interpreter included in the Java Development Kit.

attribute A property of an HTML element, specified in the start tag of the element. The attribute list of the APPLET element is used to identify the location of applet source code (with the Codebase attribute) and the name of the Java class (with the Code attribute).

block (Java) The code between matching curly braces { and }.

Boolean A data type that has a value of true or false.

browser A software program for observing the Web. A synonym for a Web client.

bytecode The machine-readable code that is created as the result of compiling a Java language source file. This is the code distributed across the network to run an applet. Bytecodes are architecture neutral; the Java-capable browser ported to a particular platform interprets them.

cast (verb) To change an expression from one data type to another.

child class A subclass of a class (its parent class). It inherits public (and protected) data and methods from the parent class.

class A template for creating objects. A class defines data and methods and is a unit of organization in a Java program. It can pass on its public data and methods to its subclasses.

compiler A software program that translates human-readable source code into machine-readable code.

constructor A method named after its class. A constructor method is invoked when an object of that class is made.

content handler A program loaded into the user’s HotJava browser that interprets files of a type defined by the Java programmer. The Java programmer provides the necessary code for the user’s HotJava browser to display/interpret this special format.

CPU Central Processing Unit.

CERN (Centre European pour la Recherche Nucleaire) The European laboratory for particle physics, where the World Wide Web originated in 1989. (See http://www.cern.ch/.)

CGI (Common Gateway Interface) A standard for programs to interface with Web servers.

client A software program that requests information or services from another software application (server) and displays this information in a form required by its hardware platform.

DTD (Document Type Definition) A specification for a markup language such as HTML.

domain name The alphanumeric name for a computer host; this name is mapped to the computer’s numeric Internet Protocol (IP) address.

element A unit of structure in an HTML document. Many elements have start and stop tags; some have just a single tag and some can contain other elements.

FTP (File Transfer Protocol) A means to exchange files across a network.

garbage collection The process by which memory allocated for objects in a program is reclaimed. Java automatically performs this process.

Gopher A protocol for disseminating information on the Internet using a system of menus.

hotspot An area on a hypertext document that a user can click on to retrieve another resource or document.

HTML (HyperText Markup Language) The mechanism used to create Web pages. Web browsers display these pages according to a browser-defined rendering scheme.

HTTP (HyperText Transfer Protocol) The native protocol of the Web, used to transfer hypertext documents.

home page An entry page for access to a local web; a page that a person or company defines as a principal page, often containing links to other pages containing personal or professional information.

HotJava A Web browser designed to execute applets written in the Java programming language.

hypermedia Hypertext that includes multimedia: text, graphics, images, sound, and video.

hypertext Text that is not constrained to a single sequence for observation; Web-based hypertext is not constrained to a single server for creating meaning.

imagemap A graphic inline image on an HTML page that potentially connects each pixel or region of an image to a Web resource. User retrieves the resources by clicking on the image.

instance An object.

interface A set of methods that Java classes can implement.

Internet The cooperatively run, globally distributed collection of computer networks that exchange information via the TCP/IP protocol suite.

Java An object-oriented programming language for creating distributed, executable applications.

Java-enabled browser A World Wide Web browser that can display Java applets.

link A connection between one hypertext document and another.

method A function that can perform operations on data.

MIME (Multipurpose Internet Mail Extensions) A specification for multimedia document formats.

Matrix The set of all networks that can exchange electronic mail either directly or through gateways. This includes the Internet, BITNET, FidoNet, UUCP, and commercial services such as America Online, CompuServe, Delphi, and Prodigy. This term was coined by John S. Quarterman in his book The Matrix (Digital Press, 1990).

Mosaic A graphical Web browser originally developed by the National Center for Supercomputing Applications (NCSA). It now includes a number of commercially licensed products.

NCSA National Center for Supercomputing Applications, at the University of Illinois at Champaign-Urbana, developers and distributors of NCSA Mosaic.

native methods Class methods that are declared in a Java class but implemented in C.

navigating The act of observing the content of the Web for some purpose.

Net An informal term for the Internet or a subset (or a superset) of the Matrix in context. For example, a computerized conference via e-mail may take place on a BITNET host that has an Internet gateway, thus making the conference available to anyone on either of these networks. In this case, the developer might say, “Our conference will be available on the Net.” One might even consider discussion forums on commercial online services to be “on the Net,” although these are not accessible from the Internet.

object A variable defined as being a particular class type. An object has the data and methods as specified in the class definition.

overload (verb) To use the same name for several items in the same scope; Java methods can be overloaded.

packet A set of data handled as a unit in data transmission.

package (Java) A set of classes with a common high-level function declared with the package keyword.

page A single file of HyperText Markup Language.

parameter (HTML) A name and value pair identified by the Name and Value attributes of the PARAM element used inside an APPLET element.

parameter list (Java) The set of values passed to a method. The definition of the method describes how these values are manipulated.

parent class The originating class of a given subclass.

protocol handler A program that is loaded into the user’s HotJava browser and interprets a protocol. These protocols include standard ones such as HTTP or programmer-defined protocols.

robot A term for software programs that automatically explore the Web for a variety of purposes. Robots that collect resources for later database queries by users are sometimes called spiders.

scope The program segment in which a reference to a variable is valid.

SGML (Standard Generalized Markup Language) A standard for defining markup languages; HTML is an instance of SGML. (See http://www.sgmlopen.org/.)

server A software application that provides information or services based on requests from client programs.

site File section of a computer on which Web documents (or other documents served in another protocol) reside—for example, a Web site, a Gopher site, or an FTP site.

Solaris Sun Microsystem’s software platform for networked applications. Solaris includes an operating system, SunOS.

Sparc (Scalable Processor ARChitecture) A microprocessor architecture based on very efficient handling of a small set of instructions. (See http://www.sparc.com/.)

spider A software program that traverses the Web to collect information about resources for later queries by users seeking to find resources. Major species of active spiders include Lycos and WebCrawler.

surfing The act of navigating the Web, typically using techniques for rapidly traversing content in order to find subjectively valuable resources.

tag The code used to make up part of an HTML element. For example, the TITLE element has a start tag, <TITLE> and an end tag, </TITLE>.

Unicode A character set that supports many world languages.

URL (Uniform Resource Locator) The scheme for addressing on the Web. A URL identifies a resource on the Web.

Usenet A system for disseminating asynchronous text discussion among cooperating computer hosts. The Usenet discussion space is divided into newsgroups, each on a particular topic or subtopic.

TCP/IP (Transmission Control Protocol/Internet Protocol) The set of protocols used for network communication on the Internet.

VRML (Virtual Reality Modeling Language) A specification for three-dimensional rendering used in conjunction with Web browsers.

web A set of hypertext pages that is considered a single work. Typically, a single web is created by cooperating authors or an author and is deployed on a single server with links to other servers—a subset of the Web.

Web (World Wide Web) A hypertext information and communication system popularly used on the Internet computer network with data communications operating according to a client/server model. Web clients (browsers) can access multi-protocol and hypermedia information using an addressing scheme.

Web server Software that provides the services to Web clients.

WWW The World Wide Web.

X X Window System. A windowing system supporting graphical user interfaces to appli-cations.

See also:

  • C++ Glossary
  • http://info.desy.de/pub/uu-gna/html/cc/text/glossary/index.html

    This glossary lists terms related to the C++ language; because C++ is closely related to Java, these terms can also be helpful.

  • Sun’s Java Glossary
  • http://java.sun.com/1.1alpha3/doc/misc/glossary.html


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