| ISP Dictionary - ISP Glossary Definitions for 'h' |
| H.323 - An ITU-T standard for transferring multimedia videoconferencing data over packet-switched networks, such as TCP/IP. There is a LAN standard for high-quality... |
| Hacker - Someone who seeks to understand computer, phone, or other systems strictly for the satisfaction of having that knowledge. Hackers wonder how things work,... |
| HAL - The portion of the operating system that lets programs deal with hardware directly. This allows programs needing more speed from the computer to bypass... |
| Half Duplex - Originally a modem communications term, half duplex now mainly refers to network communications that transmit in one direction at a time. Also see duplex... |
| Handheld Devices Markup Language - Part of the Wireless Application Protocol (WAP) , allowing text portions of Web content to be separated from graphical content for display on wireless... |
| Hard Copy - This refers to information printed out on paper, as contrasted to information stored in electronic formats. |
| Hard Disk - This is commonly the slang term for a hard drive. It refers to the type of re-writeable media that is inflexible, as opposed to a floppy disk. A hard drive... |
| Hard Drive - A device that physically stores data in your computer. It's much like a floppy disk, but the system is closed and the disks are hard (usually metal, although... |
| Hard Reset - This refers to the forced, immediate shutdown and restart of a PDA or other device by means of hardware. This is typically done by pushing a sequence of... |
| Hardware - Any physical pieces of a computer. For example, the computer chassis itself, a monitor, a printer, DRAM, and video cards are all hardware. See also software.... |
| Hardware Abstraction Layer - The portion of the operating system that lets programs deal with hardware directly. This allows programs needing more speed from the computer to bypass... |
| Hardware Compatibility List - A list of computers and peripherals that have been tested by Microsoft to work with Windows NT or Windows 2000. If you run those operating systems on equipment... |
| Hardware Emulation Layer - This provides software-based emulation of features that are not directly available in hardware. |
| Hash table - A table that contains "hash values," generally used for speeding up searching algorithms on sorted data. For example, a hash table for a dictionary might... |
| HCL - A list of computers and peripherals that have been tested by Microsoft to work with Windows NT or Windows 2000. If you run those operating systems on equipment... |
| HDML - This stands for Handheld Devices Markup Language, now called Wireless Markup Language. |
| HDSL - A form of DSL that provides T1 (1.5Mbits/second) or better transfer rates and is meant to displace business T1 connections. HDSL requires much less bandwidth... |
| HDTV - A new standard of displaying and broadcasting television signals that uses at least twice the scan lines of normal television and a 16x9 aspect ratio,... |
| Heap - Most commonly, this is a segment of memory claimed by a program. Within the heap, pieces of memory can be used and freed as needed. Depending on usage,... |
| Heatsink - A device that makes contact with a microprocessor (or other object in need of cooling) and removes heat by exchanging it with air in a more efficient manner... |
| Heatsink Fan - This is the common combination of a fan attached to a heatsink that is placed in contact with a microprocessor that needs to be cooled. The heatsink draws... |
| HEL - This provides software-based emulation of features that are not directly available in hardware. |
| Help Desk - If you've ever worked in an office environment, you may have called the help desk. This is the support organization designed to take care of your computer... |
| Hertz - A rental company, formerly represented by O.J. Simpson. It is also a measure of speed. One Hertz means one cycle per second, so one megahertz (MHz) means... |
| Hertz, Hz - Cycles per second. Used to describe the cycle rate in radio, electronics, and audio. Abbreviated Hz, and often combined with numeric prefixes, such KHz,... |
| Heterogeneous Data sources - A data-warehousing term that describes the idea of drawing data from several different (heterogeneous) data sources on different platforms and computers.... |
| Heuristics - This describes a set of rules developed to attempt to solve problems when a specific algorithm cannot be designed. For example, if the problem is "When... |
| hex, hexadecimal - Base 16 arithmetic. Conventionally, the 16 digits are represented by the digits 0 through 9 and the letters A through F. The letter A, for example, represents... |
| Hexadecimal - A base 16 number system where 16 digits are used instead of 10. In addition to the standard base 10 system numbers 0-9, letters A-F are used to represent... |
| Hibernate - This allows computer users to save the contents of their computer's memory to disk before shutting down the PC. When restarted, the contents are read back... |
| Hidden Surface Removal - This tracks the depth of each triangle in a 3D graphics representation, from the perspective of the viewer, to ensure that objects behind other objects... |
| Hierarchical relationship - This relationship is one where elements at lower levels are submissive to elements at higher levels. Just think of the military hierarchy, where the General... |
| High bit-rate DSL - A form of DSL that provides T1 (1.5Mbits/second) or better transfer rates and is meant to displace business T1 connections. HDSL requires much less bandwidth... |
| High Color - The name given to a graphics card setting that can display 16-bit color (65,536 colors). |
| High Definition Television - A new standard of displaying and broadcasting television signals that uses at least twice the scan lines of normal television and a 16x9 aspect ratio,... |
| High Performance Addressing - A form of passive matrix LCD display that improves the response time of the display. HPA screens still suffer from the same contrast problems that make... |
| High-Speed SDRAM - A form of SDRAM memory made by Enhanced Memory Systems. It is designed to operate comfortably at speeds of up to 150MHz or higher at CAS 2 latency levels.... |
| Hit - When a user requests an HTML document, image, or external object on the World Wide Web, the server records that request as a "hit." The problem with measuring... |
| hoax - There are many hoaxes continually popping up on the nets. False viruses are the most common of these with names like "Join the Crew" or "PenPal Greetings",... |
| Holographic Storage - This form of storing data uses a three-dimensional array of storage media. Lasers are aligned vertically and horizontally to read or write a specific section... |
| home page - A home page is a web page. In most familiar terms, it is a personal page for an individual. It can also be the basic main page for a more complex web site... |
| Homepage - A page on the World Wide Web (WWW) that is the first page of a website. Usually it is called index.html or index.htm. When you go to a Web address, this... |
| Honeypot - A system left open and unprotected to entice hackers to break into it. Usually this is done so that system administrators can monitor the methods used... |
| Host - A generic term used to describe a computer or program that makes a resource available, usually over a network. It is often used as a prefix along with... |
| Host adapter - This term is synonymous with SCSI adapter. It refers to an add-in board, such as a PCI SCSI card, that allows PCs to communicate with SCSI devices. |
| Hosts - A file used by many operating systems, like the LMHosts file, to map IP addresses to host names. It's used mainly for small network installations where... |
| Hot Spare - A drive in a RAID configuration that sits idle until one of the RAIDed drives fails. The hot spare then assumes the role of the dead drive. When the dead... |
| Hot-pluggable - Same as hot-swappable, but also connotes a simple plug-in mechanism for easy swapping. |
| Hot-swappable - This type of mechanism implies that you can remove or add things while the system is powered on and running. For example, hard drives and power supplies... |
| HPA - A form of passive matrix LCD display that improves the response time of the display. HPA screens still suffer from the same contrast problems that make... |
| HSDRAM - A form of SDRAM memory made by Enhanced Memory Systems. It is designed to operate comfortably at speeds of up to 150MHz or higher at CAS 2 latency levels.... |
| HSF - This is the common combination of a fan attached to a heatsink that is placed in contact with a microprocessor that needs to be cooled. The heatsink draws... |
| HTML - HyperText Markup Language. The coding system used to create WWW pages. A page written in HTML is a text file that includes tags in angle brackets that... |
| http - HyperText Transfer Protocol. It is the main protocol used on the World Wide Web that enables linking to other web sites. Addressing to other web... |
| HTTPS - A secure means of transferring data using the HTTP protocol. Typically HTTP data is sent over TCP/IP port 80, but HTTPS data is sent over port 443. This... |
| hub - A device that connects the cables from computers and other devices such as printers in an ethernet local area network. Traditionally, hubs are used for... |
| Hyper Text Transfer Protocol - The way the data in an HTML document is transferred. A document coming in over the HTTP protocol, usually TCP/IP port 80, is read as an HTML document.... |
| hyperlink - A link in a web page that brings you to another location or resource when activated. Hyperlinks usually appear as underlined text and printed in a contrasting... |
| hypermedia - Like hypertext, but includes other interlinking media, such as graphics, audio, video, and VRML. |
| hypertext - A form of text which includes visible links to other pages of text or media, accessible by clicking or selecting the links. |
| HyperText Markup Language - A standard language initially created for typesetting. Although it is a language, it isn't really a programming language. It is mainly used for creating... |
| Hypertext Preprocessor - Created in 1994, this is a versatile embedded scripting language that can be placed into HTML documents. As long as the webserver supports it, PHP can... |
| HyperTransport - An industry standard serial connection method pioneered by AMD for the internal connection of different buses inside of a PC or network device. It initially... |
| H_Key - A part of the Windows registry hive. The hive contains several different pieces, or keys. |
