Reference Guide

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HTTP — hypertext transfer protocol — A protocol for exchanging files between
computers connected to the Internet.
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.
IrDA — Infrared Data Association — The organization that creates international
standards for infrared communications.
IRQ — interrupt request — An electronic pathway assigned to a specific device so
that the device can communicate with the processor. Each device connection must be
assigned an IRQ. Although two devices can share the same IRQ assignment, you
cannot operate both devices simultaneously.
ISP — Internet service provider — A company that allows you to access its host server
to connect directly to the Internet, send and receive e-mail, and access websites. The
ISP typically provides you with a software package, user name, and access phone
numbers for a fee.