MICROSOFT Computer Dictionary, Fifth Edition

Microsoft Computer Dictionary, Fifth Edition

n. 1. A successful retrieval of data from a cache rather than from the slower hard disk or RAM. See also cache, hard disk, RAM. 2. A successful retrieval of a record matching a query in a database. See also query (definition 1), record1. 3. Retrieval of a file from a Web site. Each separate file accessed on a Web page, including HTML documents and graphics, counts as a hit. 4. In computer war and other games, when a character is successfully fired on, attacked, or otherwise taken out.

hit points

n. Used in most computer and console war games to refer to the amount of times a player can be damaged before his or her character passes out or dies.

hive

n. One of the top-level sets of keys, subkeys, and values in Windows 9x, Windows NT, Windows 2000, and Windows CE Registries. The term was created by a Microsoft programmer who thought the structure of the Registry resembled a beehive. Each hive is a permanent part of the Registry and is associated with a set of files containing information related to the configuration (applications, user preferences, devices, and so on) of the computer on which the operating system is installed. Registry hives include HKEY_LOCAL_MACHINE, HKEY_CURRENT_USER, and HKEY_CURRENT_CONFIG. See also Registry.

HKEY

n. Short for hkey handle. In Windows 9x, Windows NT, and Windows 2000, a handle to a Registry key in which configuration information is stored. Each key leads to subkeys containing configuration information that, in earlier versions of Windows, was stored in .ini files. For example, the handle key HKEY_CURRENT_USERControl Panel leads to the subkey for the Windows Desktop. See also handle (definition 1).

HLL

n. See high-level language.

HLS

n. Acronym for hue-lightness-saturation. See HSB.

HMA

n. See high memory area.

HMD

n. See head-mounted device.

Hollerith tabulating/recording machine

n. An electromechanical machine invented by Herman Hollerith in the late 1800s for processing data supplied in the form of holes punched at predetermined locations in cards. Contacts made through the holes completed electrical circuits, allowing signals to be passed to counting and tabulating devices. This machine is considered to have reduced the time required to finish the 1890 U.S. census by two-thirds. Such machines were manufactured in the early 1900s by Hollerith’s Tabulating Machine Company, which eventually became the International Business Machines Corporation (IBM).

hologram

n. A three-dimensional image record created by holography. The hologram consists of a light interference pattern preserved in a medium such as photographic film. When suitably illuminated, it produces an image that changes its appearance as the viewer changes viewing angle. See also holography.

holography

Microsoft Computer Dictionary, Fifth Edition

n. A method of reproducing three-dimensional visual images by recording light interference patterns on a medium such as photographic film, creating a hologram. See also hologram.

holy war

n. 1. A widespread and acrimonious debate among computer professionals over some aspect of the computer field, such as the debate over use of the GOTO statement in programming or that over big-endian versus little-endian data storage. 2. An argument in a mailing list, newsgroup, or other forum over some emotional and controversial topic, such as abortion or Northern Ireland.

Introducing a holy war that is off the purported topic of the forum is considered a violation of netiquette.

home

n. A beginning position, such as the upper left corner of a character-based display, the left end of a line of text, cell A1 of a spreadsheet, or the top of a document.

home automation

n. The process of programmatically controlling appliances, lighting, heating and cooling systems, and other devices in a home network. See also home network (definition 1).

homebrew

n. Hardware or software developed by an individual at home or by a company for its own use rather than as a commercial product, such as hardware developed by electronics hobbyists when microcomputers first appeared in the 1970s.

home computer

n. A personal computer designed and priced for use in the home.

home controller

n. A software or hardware interface used to control the systems in a home network for home automation.

home directory

n. A directory associated with a user account under UNIX. The home directory is the current directory when the user first logs in, and the user can return to it by entering the command cd (change directory) without a pathname. The user’s files will ordinarily be stored in the home directory and its descendants.

homegrown software

n. Software developed by an individual at home rather than in a professional environment. Most public-domain and shareware programs are created this way.

Home key

n. A key, found on most keyboards, whose function usually involves sending the cursor to some type of home position in an application. See also home.

home network

n. 1. A communications network in a home or building used for home automation. Home networks can use wiring (existing or new) or wireless connections. See also home automation, home controller. 2. Two or more computers in a home that are interconnected to form a local area network (LAN).

home office

n. 1. An office set up within a residence. 2. The main headquarters of a company.

home page

Microsoft Computer Dictionary, Fifth Edition

n. 1. A document intended to serve as a starting point in a hypertext system, especially the World Wide Web. A home page is called a start page in Microsoft Internet Explorer. 2. An entry page for a set of Web pages and other files in a Web site. 3. A personal Web page, usually for an individual.

Home Phoneline Networking Alliance n. See HomePNA.

HomePNA

n. Short for Home Phoneline Networking Alliance. An association of more than 100 companies working toward the adoption of a unified technology for setting up home networks over existing telephone wiring. Phoneline networking allows multiple PCs, printers, and peripheral devices to be connected for such purposes as multiplayer gaming, sharing printers and other peripherals, and rapid downloads over the Internet. The alliance was founded by a number of companies including IBM, Intel, AT&T, and Lucent Technologies.

Home Radio Frequency n. See HomeRF.

home record

n. See header record.

HomeRF

n. Acronym for Home Radio Frequency. A wireless home-networking specification that uses the 2.4-GHz frequency band to communicate between computers, peripherals, cordless phones, and other devices. HomeRF is supported by Siemens, Compaq, Motorola, National Semiconductor, Proxim, and other companies.

homogeneous environment

n. A computing milieu, usually within an organization, in which only one manufacturer’s hardware and one manufacturer’s software are used. Compare heterogeneous environment.

homogeneous network

n. A network on which all the hosts are similar and only one protocol is used.

Honeynet Project

n. A nonprofit security research group created to collect and analyze data on hacking tools and methods by maintaining a decoy network of computers that is potentially attractive to hackers. The Honeynet Project sets up entire networks of computers in different combinations of operating systems and security to realistically simulate those used in businesses and organizations. Hackers are lured to the network where all inbound and outbound data is captured and contained to help researchers learn about hacker tactics and motives.

honeypot

n. A security program designed to lure and distract a network attacker with decoy data. The honeypot appears to be a system that the intruder would like to crack but which, in reality, is safely separated from the actual network. This allows network administrators to observe attackers and study their activities without the intruders knowing they are being monitored. Honeypot programs get their name from the “like a bear to honey” metaphor.

honker

n. A slang term for a hacker, the term originated in China. The Honker Union of China is an active group of Chinese hackers with nationalistic or hacktivist aims. The Honker Union of China has claimed patriotic motivation for defacing Japanese and U.S. Web sites, hacking U.S. networks, and releasing the Lion worm and other malicious programs. See also hacktivist, Lion worm.

Microsoft Computer Dictionary, Fifth Edition

hook

n. A location in a routine or program in which the programmer can connect or insert other routines for the purpose of debugging or enhancing functionality.

hop

n. In data communications, one segment of the path between routers on a geographically dispersed network. A hop is comparable to one “leg” of a journey that includes intervening stops between the starting point and the destination. The distance between each of those stops (routers) would be a communications hop.

horizontal blanking interval

n. See blanking, horizontal retrace.

horizontal flyback

n. See horizontal retrace.

horizontal market

n. A broad category of business activity, such as accounting or inventory control, that carries across many types of business. Compare vertical market.

horizontal market software

n. Application programs, such as word processors, that can be used in all types of business, as opposed to those geared for a certain industry.

horizontal retrace

n. The movement of the electron beam in a raster-scan video display from the right end of one scan line to the left end (the beginning) of the next. During horizontal retrace, the electron beam is turned off, so the time required for the beam to move is called the horizontal blanking interval. See also blanking. Compare vertical retrace.

horizontal scrolling

n. A feature of programs such as word processors and spreadsheets that enables the user to scroll left and right to display information beyond the horizontal limits of the screen (or window, in a graphical user interface).

horizontal synchronization

n. On raster displays, the timing produced by a signal that controls the sweep of the display’s electron beam as it moves from left to right and back again to form an image line by line. The horizontal synchronization signal is usually controlled by a circuit known as a phase-locked loop, which maintains a constant precise frequency so that a clear image is formed.

host1

n. 1. The main computer in a mainframe or minicomputer environment—that is, the computer to which terminals are connected. 2. In PC-based networks, a computer that provides access to other computers. 3. On the Internet or other large networks, a server computer that has access to other computers on the network. A host computer provides services, such as news, mail, or data, to computers that connect to it.

host2

vb. To provide services to client computers that connect from remote locations—for example, to offer Internet access or to be the source for a news or mail service.

host adapter

n. A device for connecting a peripheral to the main computer, typically in the form of an expansion card. Also called: controller, host bus adapter.

Microsoft Computer Dictionary, Fifth Edition

hosting

n. The practice of providing computer and communication facilities to businesses or individuals, especially for use in creating Web and electronic commerce sites. A hosting service can provide high-speed access to the Internet, redundant power and data storage, and 24-hour maintenance at lower cost than implementing the same services independently. See also host2, virtual hosting.

Host Integration Server

n. A software application from Microsoft Corporation to allow businesses to integrate existing application, data, and network assets with new business applications and technologies. Host Integration Server preserves a company’s existing legacy infrastructure and investments, while providing out-of-the-box development tools that enable integration with client/ server and Web networks.

host language

n. 1. The machine language of a CPU. 2. A high-level language that is specifically supported by an operating system with its toolbox routines and native development systems.

host name

n. The name of a specific server on a specific network within the Internet, leftmost in the complete host specification. For example, www.microsoft.com indicates the server called “www” within the network at Microsoft Corporation.

host not responding

n. An error message issued by an Internet client indicating that the computer to which a request has been sent is refusing the connection or is otherwise unavailable to respond to the request.

host replacement n. See rehosting.

host timed out

n. An error condition that occurs when a remote system fails to respond within a reasonable amount of time (a few minutes) during an exchange of data over a TCP connection. This condition may mean that the remote system has crashed or been disconnected from the network. The error message the user sees may or may not be phrased in this manner. See also TCP. Compare host not responding.

host unreachable

n. An error condition that occurs when the particular computer to which the user wishes to connect over a TCP/IP network cannot be accessed on its LAN because it is either down or disconnected from the network. The error message the user sees may or may not be phrased in this manner. See also TCP/IP.

hot

adj. Of special or urgent interest, or deemed popular.

HotBot

n. An Internet search engine developed by Inktomi Corporation and HotWired, Inc. Using Slurp, a Web robot, this tool maintains a database of documents that can be matched to key words entered by the user, in a fashion similar to other search engines. HotBot incorporates many workstations in parallel to search and index Web pages. See also spider.

hot carrier diode

n. See Schottky diode.

hot docking

Microsoft Computer Dictionary, Fifth Edition

n. The process of attaching a laptop computer to a docking station while the computer is running, and automatically activating the docking station’s video display and other functions. See also docking station, laptop.

hot insertion

n. The insertion of a device or card while there is power to the system. Many newer laptops allow for hot insertion of PCMCIA cards. High-end servers may also allow hot insertion to reduce downtimes.

HotJava

n. A Web browser developed by Sun Microsystems, Inc., that is optimized to run Java applications and applets embedded in Web pages. See also applet, Java, Java applet.

hot key1

n. A keystroke or combination of keystrokes that switches the user to a different program, often a terminate-and-stay-resident (TSR) program or the operating system user interface. See also TSR.

hot key2

vb. To transfer to a different program by pressing a hot key.

hot link

n. A connection between two programs that instructs the second program to make changes to data when changes occur in the first program. For example, a word processor or desktop publishing program could update a document based on information obtained from a database through a hot link. See hyperlink.

hotlist

n. A list of frequently accessed items, such as Web pages in a Web browser, from which the user can select one. The hotlist of Web pages is called the bookmark list in Netscape Navigator and Lynx and is called the Favorites folder in Microsoft Internet Explorer.

Hotmail

n. A Web-based e-mail service launched in 1996 and owned and operated by Microsoft since December 1997. Hotmail provides free e-mail accounts and can be used by anyone with Internet access and Web browsing software.

hot plugging

n. A feature that allows equipment to be connected to an active device, such as a computer, while the device is powered on.

hot-potato routing

n. A packet routing scheme that relies on keeping data moving, even if it may temporarily move away from its final destination. Also called: deflection routing.

hot spare

n. In RAID (redundant array of independent disks) systems, a spare drive in the array that is configured as a backup on which data can be rebuilt in the event that another drive fails. Hot spares are kept on line and do not require operator intervention to be activated. See also RAID.

hot spot

n. The position in a mouse pointer, such as the position at the tip of an arrow or the intersection of the lines in a cross, that marks the exact location that will be affected by a mouse action, such as a button press.

hot swapping

Microsoft Computer Dictionary, Fifth Edition

n. See hot plugging.

HotSync

n. Software application from Palm that permits data synchronization between a Palm handheld computing device and another computing device, such as a laptop or personal computer. The synchronization occurs via a cable connection or wirelessly (for example, via infrared signals).

HotWired

n. A Web site affiliated with Wired magazine that contains news, gossip, and other information about the culture of the Internet.

housekeeping

n. Any of various routines, such as updating the clock or performing garbage collection, designed to keep the system, the environment within which a program runs, or the data structures within a program in good working order.

hover button

n. Text or an image on a Web page, usually in the form of a button, that changes appearance when a cursor passes over it. The hover button may change color, blink, display a pop-up with additional information, or produce other similar effects. Hover buttons are usually implemented through ActiveX objects and scripting, although hover behavior can also be set through HTML attributes.

HPC

n. See handheld PC.

HPFS

n. Acronym for High Performance File System. A file system available with OS/2 versions 1.2 and later. See also FAT file system, NTFS.

HPGL

n. Acronym for Hewlett-Packard Graphics Language. A language originally developed for images destined for plotters. An HPGL file consists of instructions that a program can use to reconstruct a graphical image.

HPIB

n. Acronym for Hewlett-Packard Interface Bus. See general-purpose interface bus.

HPPCL

n. Acronym for Hewlett-Packard Printer Control Language. See Printer Control Language.

HP/UX or HP-UX

n. Acronym for Hewlett-Packard UNIX. A version of the UNIX operating system specifically designed to be run on Hewlett-Packard’s workstations. See also UNIX.

.hqx

n. A file extension for a file encoded with BinHex. See also BinHex.

HREF

n. Short for hypertext reference. An attribute in an HTML document that defines a link to another document on the Web. See also HTML.

HSB

n. Acronym for hue-saturation-brightness. A color model in which hue is the color itself as placed on a color wheel, where 0° is red, 60° is yellow, 120° is green, 180° is cyan, 240° is blue, and 300° is magenta; saturation is the percentage of the specified hue in the color; and brightness is

Microsoft Computer Dictionary, Fifth Edition

the percentage of white in the color. Also called: HLS, HSV, hue. See also color model. Compare CMY, RGB.

HSM

n. Short for Hierarchical Storage Management. A technology for managing online data and data storage in which the medium on which the information resides is linked to the frequency with which the information is accessed. By migrating data to and from primary (rapidly accessed but expensive) and secondary (slower but less expensive) storage, HSM maintains often-used information on primary storage media and less frequently used data on secondary storage such as tape or an optical jukebox. Although information resides on different storage media, all of it appears to be on line and remains accessible to the user. When users request data residing on secondary storage, HSM moves the information back to the primary storage medium.

HSV

n. Acronym for hue-saturation-value. See HSB.

H-sync

n. See horizontal synchronization.

HTCPCP

n. Acronym for Hyper Text Coffee Pot Control Protocol. A protocol defined in jest as an April Fools’ Day spoof of open Internet standards. HTCPCP/1.0 was proposed in RFC 2324 on April 1, 1998 by Larry Masinter of Xerox PARC. In this RFC, Masinter described a protocol for controlling, monitoring, and diagnosing coffee pots.

.htm

n. The MS-DOS/Windows 3.x file extension that identifies Hypertext Markup Language (HTML) files, most commonly used as Web pages. Because MS-DOS and Windows 3.x cannot recognize file extensions longer than three letters, the .html extension is truncated to three letters in those environments. See also HTML.

.html

n. The file extension that identifies Hypertext Markup Language (HTML) files, most commonly used as Web pages. See also HTML.

HTML

n. Acronym for Hypertext Markup Language. The markup language used for documents on the World Wide Web. A tag-based notation language used to format documents that can then be interpreted and rendered by an Internet browser. HTML is an application of SGML (Standard Generalized Markup Language) that uses tags to mark elements, such as text and graphics, in a document to indicate how Web browsers should display these elements to the user and should respond to user actions such as activation of a link by means of a key press or mouse click. HTML 2, defined by the Internet Engineering Task Force (IETF), included features of HTML common to all Web browsers as of 1994 and was the first version of HTML widely used on the World Wide Web. HTML+ was proposed for extending HTML 2 in 1994, but it was never implemented. HTML 3, which also was never standardized or fully implemented by a major browser developer, introduced tables. HTML 3.2 incorporated features widely implemented as of early 1996, including tables, applets, and the ability to flow text around images. HTML 4, the latest specification, supports style sheets and scripting languages and includes internationalization and accessibility features. Future HTML development will be carried out by the World Wide Web Consortium (W3C). Most Web browsers, notably Netscape Navigator and Internet Explorer, recognize HTML tags beyond those included in the present standard. See also

.htm, .html, SGML, tag (definition 3), Web browser.

HTML attribute

Microsoft Computer Dictionary, Fifth Edition

n. A value within an HTML tag that assigns additional properties to the object being defined. Some HTML editing software assigns some attributes automatically when you create an object such as a paragraph or table.

HTML code fragment

n. HTML code that you add to a Web page to create features such as a script, a counter, or a scrolling marquee. Often used in the context of webrings to add a link and standard graphics or automation to an individual page to indicate membership.

HTML document

n. A hypertext document that has been coded with HTML. See Web page.

HTML editor

n. A software program used to create and modify HTML documents (Web pages). Most HTML editors include a method for inserting HTML tags without actually having to type out each tag. A number of HTML editors will also automatically reformat a document with HTML tags, based on formatting codes used by the word processing program in which the document was created. See also tag (definition 3), Web page.

HTML extensions

n. A feature or setting that is an extension to the formal HTML specification. Extensions may not be supported by all Web browsers, but they may be used widely by Web authors. An example of an extension is marquee scrolling text.

HTML page

n. See Web page.

HTML server control

n. An ASP.NET server control that belongs to the System.Web.UI.HtmlControls namespace. An HTML server control maps directly to an HTML element and is declared on an ASP.NET page as an HTML element marked by a runat=server attribute. In contrast to Web server controls, HTML server controls do not have an <asp:ControlName> tag prefix. See also Web server control.

HTML source

n. See source (definition 2).

HTML source file

n. See source (definition 2).

HTML tag

n. See tag (definition 3).

HTML validation service

n. A service used to confirm that a Web page uses valid HTML according to the latest standard and/or that its hyperlinks are valid. An HTML validation service can catch small syntactical errors in HTML coding as well as deviations from the HTML standards. See also HTML.

HTTP

n. Acronym for Hypertext Transfer Protocol. The protocol used to carry requests from a browser to a Web server and to transport pages from Web servers back to the requesting browser. Although HTTP is almost universally used on the Web, it is not an especially secure protocol.

HTTPd

n. Acronym for Hypertext Transfer Protocol Daemon. A small, fast HTTP server that was available free from NCSA. HTTPd was the predecessor for Apache. Also called: HTTP Daemon. See also Apache, HTTP server, NCSA (definition 1).

Microsoft Computer Dictionary, Fifth Edition

HTTP Daemon n. See HTTPd.

HTTP Next Generation n. See HTTP-NG.

HTTP-NG

n. Acronym for Hypertext Transfer Protocol Next Generation. A standard under development by the World Wide Web Consortium (W3C) for improving performance and enabling the addition of features such as security. Whereas the current version of HTTP establishes a connection each time a request is made, HTTP-NG will set up one connection (which consists of separate channels for control information and data) for an entire session between a particular client and a particular server.

HTTPS

n. 1. Acronym for Hypertext Transfer Protocol Secure. A variation of HTTP that provides for encryption and transmission through a secure port. HTTPS was devised by Netscape and allows HTTP to run over a security mechanism known as SSL (Secure Sockets Layer). See also HTTP, SSL. 2. Web server software for Windows NT. Developed by the European Microsoft Windows NT Academic Centre (EMWAC) at the University of Edinburgh, Scotland, it offers such features as WAIS search capability. See also HTTP server, WAIS.

HTTP server

n. 1. Server software that uses HTTP to serve up HTML documents and any associated files and scripts when requested by a client, such as a Web browser. The connection between client and server is usually broken after the requested document or file has been served. HTTP servers are used on Web and Intranet sites. Also called: Web server. See also HTML, HTTP, server (definition 2). Compare application server. 2. Any machine on which an HTTP server program is running.

HTTP status codes

n. Three-digit codes sent by an HTTP server that indicate the results of a request for data. Codes beginning with 1 respond to requests that the client may not have finished sending; with 2, successful requests; with 3, further action that the client must take; with 4, requests that failed because of client error; and with 5, requests that failed because of server error. See also 400, 401, 402, 403, 404, HTTP.

HTTP streaming

n. The process of downloading streaming digital media using an HTTP server (a standard Internet server) rather than a server designed specifically to transmit streaming media. HTTP streaming downloads the media file onto a computer, which plays the downloaded file as it becomes available. See also real-time streaming.

hub

n. In a network, a device joining communication lines at a central location, providing a common connection to all devices on the network. The term is an analogy to the hub of a wheel. See also active hub, switching hub.

hue

n. In the HSB color model, one of the three characteristics used to describe a color. Hue is the attribute that most readily distinguishes one color from other colors. It depends on the frequency of a light wave in the visible spectrum. See also color model, HSB. Compare brightness, saturation (definition 2).

Huffman coding