System information

Glossary
g-27
Glossary
graphical user
interface
GUI. A visually oriented interface where the user interacts with
representations of real-world objects displayed on the computer
screen. Interactions with such objects produce actions that are
intuitive to the user (D).
ground That portion of a conducting circuit connected to the earth (D).
GSM card A generic port (G_Port) module card containing shortwave laser
ports for multimode fiber-optic cables.
GUI See graphical user interface.
H
half duplex The capacity to transmit in two directions, but not simultaneously.
hard drive An electromechanical device used for information storage and
retrieval, incorporating one or more rotating disks on which data is
recorded, stored, and read magnetically.
hardware Physical equipment (director, switch, or personal computer) as
opposed to computer programs or software.
hardware
management console
The console runs the Hardware Management console application
(HWMCA), and is the operations and management personal
computer (PC) platform for S/390 and z/Series servers.
HBA See host bus adapter.
Hertz Hz. A unit of frequency equal to one cycle per second.
heterogeneous fabric A fabric containing open-fabric-compliant products from various
vendors. Contrast with
homogeneous fabric.
hexadecimal A numbering system with base of sixteen; valid numbers use the
digits 0 through 9 and characters A through F, where A represents 10
and F represents 15 (D).
high availability A performance feature characterized by hardware component
redundancy and concurrent maintenance. High-availability systems
maximize system uptime while providing superior reliability,
availability, and serviceability.