Personal Computer User Manual

Glossary 191
H
hard drive — A drive that reads and writes data on a hard disk. The terms hard drive
and hard disk are often used interchangeably.
heat sink — A metal plate on some processors that helps dissipate heat.
hibernate mode — A power management mode that saves everything in memory to a
reserved space on the hard drive and then turns off the computer. When you restart
the computer, the memory information that was saved to the hard drive is
automatically restored.
HTTP — hypertext transfer protocol — A protocol for exchanging files between
computers connected to the Internet.
Hyper-Threading — Hyper-Threading is an Intel technology that can enhance overall
computer performance by allowing one physical processor to function as two logical
processors, capable of performing certain tasks simultaneously.
Hz — hertz — A unit of frequency measurement that equals 1 cycle per second.
Computers and electronic devices are often measured in kilohertz (kHz), megahertz
(MHz), gigahertz (GHz), or terahertz (THz).
I
IC — integrated circuit — A semiconductor wafer, or chip, on which thousands or
millions of tiny electronic components are fabricated for use in computer, audio, and
video equipment.
IDE — integrated device electronics — An interface for mass storage devices in which
the controller is integrated into the hard drive or CD drive.
IEEE 1394 — Institute of Electrical and Electronics Engineers, Inc. — A high-
performance serial bus used to connect IEEE 1394-compatible devices, such as digital
cameras and DVD players, to the computer.
infrared sensor — A port that allows you to transfer data between the computer and
infrared-compatible devices without using a cable connection.
integrated — Usually refers to components that are physically located on the
computer’s system board. Also referred to as built-in.
I/O — input/output — An operation or device that enters and extracts data from your
computer. Keyboards and printers are I/O devices.
I/O address — An address in RAM that is associated with a specific device (such as a
serial connector, parallel connector, or expansion slot) and allows the processor to
communicate with that device.