Software Engineering Glossary

"H" Glossary Content



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Other topics within the glossary:

halt
  1. Most commonly, a synonym for stop.
  2. Less commonly, a synonym for pause.
hard failure
A failure that results in complete shutdown of a system. Contrast with: soft failure.
hardware
Physical equipment used to process, store, or transmit computer programs or data Contrast with: software.
hardware configuration item (HWCI)
An aggregation of hardware that is designated for configuration management and treated as a single entity in the configuration management process. Contrast with: computer software configuration item. See also: configuration item.
hardware design language (HDL)
A language with special constructs and, sometimes, verification protocols, used to develop, analyze, and document a hardware design. See also: program design language.
hardware monitor
  1. A device that measures or records specified events or characteristics of a computer system; for example, a device that counts the occurrences of various electrical events or measures the time between such events.
  2. A software tool that records or analyzes hardware events during the execution of a computer program. See also: monitor; software monitor.
HDL
Acronym for hardware design language. See: design language.
header
  1. A block of comments placed at the beginning of a computer program or routine.
  2. Text that appears at the top of every page of a document when it is printed, such as a chapter title.
  3. Identification or control information placed at the beginning of a file or message. Contrast with: trailer.
header information
Information that contains PostScript® instructions required for printing documents correctly on a PostScript printer.
Help button bar
Contains the Help buttons you can use to move to topics. It is located directly below the menu bar.
help button: <<
Displays the previous topic in a series of topics. Use this button to move backward from topic to topic in the order they are organized in Help. This button is located in the Help button bar, directly below the menu bar.
help button: >>
Displays the next topic in a series of topics. Use this button to move forward from topic to topic in the order they are organized in Help. This button is located in the Help button bar, directly below the menu bar.
hierarchical decomposition
A type of modular decomposition in which a system is broken down into a hierarchy of components through a series of top-down refinements. See also: functional decomposition; stepwise refinement.
hierarchical input-process-output (HIPO)
See: input-process-output.
hierarchical modeling
A technique used in computer performance evaluation, in which a computer system is represented as a hierarchy of subsystems, the subsystems are analyzed to determine their performance characteristics, and the results are used to evaluate the performance of the overall system.
hierarchy
A structure in which components are ranked into levels of subordination; each component has zero, one, or more subordinates; and no component has more than one superordinate component. See also: hierarchical decomposition; hierarchical modeling.
hierarchy chart
See: structure chart.
high level language
See: high order language.
high memory area
The first 64K of extended memory (often referred to as HMA).
high order language (HOL)
A programming language that requires little knowledge of the computer on which a program will run, can be translated into several different machine languages, allows symbolic naming of operations and addresses, provides features designed to facilitate expression of data structures and program logic, and usually results in several machine instructions for each program statement. Examples include Ada, COBOL, FORTRAN, ALGOL, PASCAL. Syn: high level language; higher order language; third generation language. Contrast with: assembly language; fifth generation language; fourth generation language; machine language.
higher order language
See: high order language.
History button
Displays a list of Help topics you have viewed. Use this button to revisit any of the last 40 Help topics you have viewed. The most recent topic appears first. The History button is in the Help button bar, directly below the menu bar.
HLL
Acronym for high level language. See: high order language.
HMI
Acronym for human-machine interface. See: user interface.
HOL
Acronym for high order language.
homogeneous redundancy
In fault tolerance, realization of the same function with identical means, for example, use of two identical processors. Contrast with: diversity.
horizontal microinstruction
A microinstruction that specifies a set of simultaneous operations needed to carry out a given machine language instruction. Note: Horizontal microinstructions are relatively long, often 64 bits or more, and are called "horizontal" because the set of simultaneous operations that they specify are written on a single line, rather than being listed sequentially down the page. Contrast with: diagonal microinstruction; vertical microinstruction.
host computer
A computer used to develop software.
Contast with: target computer for contrast.
host machine
  1. A computer used to develop software intended for another computer. Contrast with: target machine (1).
  2. A computer used to emulate another computer. Contrast with: target machine (2).
  3. The computer on which a program or file is installed.
  4. In a computer network, a computer that provides processing capabilities to users of the network.
housekeeping operation
A computer operation that establishes or reestablishes a set of initial conditions to facilitate the execution of a computer program; for example, initializing storage areas, clearing flags, rewinding tapes, opening and closing files. Syn: overhead operation.
hue
The position of a color along the color spectrum. For example, green is between yellow and blue.
human-machine interface (HMI)
See: user interface.
HWCI
Acronym for hardware configuration item.
hybrid coupling
A type of coupling in which different subsets of the range of values that a data item can assume are used for different and unrelated purposes in different software modules. Contrast with: common-environment coupling; content coupling, control coupling; data coupling; pathological coupling.