Glossary of Computer Terms—H

Glossary of Computer Terms—H

H

HACKER: A person with technical expertise who experiments with computer systems to determine how to develop additional features. Hackers are occasionally requested by system administrators to try and “break into” systems via a network to test security. The term hacker is sometimes incorrectly used interchangeably with cracker. A hacker is called a “white hat” and a cracker a “black hat.”

HALF-DUPLEX: A communications mode that allows transmission and reception of digital data between computers, but not simultaneously.

HANDSHAKING: The process by which two devices initiate communications. Handshaking begins when one device sends a message to another device indicating that it wants to establish a communications channel. The two devices then send several messages back and forth that enable them to agree on a communications protocol.

HARD COPY: A paper printout of what you have prepared on the computer.

HARDWARE: The physical and mechanical components of a computer system, such as the electronic circuitry, chips, monitor, disks, disk drives, keyboard, modem, and printer.

HARD-DISK DRIVE: A sealed unit containing high-density, high-speed, rigid metal disks, and recording heads to store digital data. It reads and writes data faster than floppy disks.

HELPER APPLICATION: This is an application your browser uses to manipulate a downloaded program.

HEXADECIMAL: The base 16 number system using 16 symbols (0 to 9 and A to F) to represent 16 decimal numerals (0 to 15).

HIGH-LEVEL LANGUAGE (HLL): A programming language (source code) consisting of a unique group of symbols and command statements representing a series of machine operations. A COMPILER or INTERPRETER translates (converts) a HLL into MACHINE LANGUAGE. BASIC, FORTRAN, PASCAL, ALGOL, and ADA are some examples of high-level languages.

HOME PAGE: The main page of a Web site used to greet visitors, provide information about the site, or to direct the viewer to other pages on the site.

HOST: A computer that “hosts” outside computer users by providing files, services or sharing its resources. INAs Web site is a hosted site. Having a hosted site has the advantage for a company of not having to worry about security, maintenance or upgrading. The disadvantage is a loss of control over these issues, although it is relatively easy to move to a new host.

HOTLIST: List of URLs saved within the Mosaic Web browser. (Bookmark in Netscape.)

HTML: (Hypertext Markup Language) The basic language that is used to build hypertext documents on the World Wide Web.

HTTP: (Hypertext Transfer Protocol) The set of rules (protocol) used by the computers to transfer hypertext documents over the internet.

HYPERTEXT: Text in a document that contains a hidden link to other text. You can click a mouse on a hypertext word and it will take you to the text designated in the link. The wonderful thing about hypertext, however, is its ability to link—using http over the World Wide Web—to any Web document.

HYPERLINK: Text or an image that is connected by hypertext coding to a different location. By selecting the text or image with a mouse, the computer “jumps to” (or displays) the linked text. 
HYPERMEDIA: Integrates audio, graphics, and/or video through links embedded in the main program.