PC Hardware

Technical Terms Beginning With I


A small picture on a computer screen that represents a group of files, an object, or operations. A user accesses the item he or she wants by clicking on the picture with the mouse.

image map

A "clickable" graphic that performs different actions depending on where in the graphic the user clicks.

Industry Standard Architecture (ISA)

One of several common expansion slot and card designs.

integrated circuit (IC)

An electronic device consisting of many miniature transistors and other circuit elements (resistors and capacitors and so forth).

Integrated Drive Electronics (IDE)

The most common standard for interfacing hard disk and CD-ROM drives in the PC environment. Much of the actual work of controlling the hard disk drive is handled by the system BIOS. This reduces hardware cost, but introduces an overall system performance penalty during I/O operations. See also Enhanced IDE (EIDE)

internal cache

High-speed memory built into the processor to store frequently used data. This avoids accessing slower devices such as RAM or hard drives.

International Organization for Standardization (ISO)

Groups of experts drawn from the industry that set standards for various technologies. The work of these teams has led to development of SCSI, SMAL and the Internet, and the ASCII character set.


A system that links computer networks all over the world.

I/O address

A unique name assigned to each device that allows the CPU to recognize the device with which it is communicating.

IP (Internet Protocol)

The protocols used to define how data is transmitted over the Internet.

IP address (Internet Protocol address)

A unique address that identifies every network and host on the Internet. (A host is defined as the TCP/IP network interface within the computer, not the computer itself-a computer with two network cards will have two IP addresses.)

IPX/SPX (Internetwork Packet Exchange/Sequenced Packet Exchange)

NetWare core protocol developed by Novell in the early 1980s.

IRQ (interrupt request)

A wire used by the CPU to control the flow of data. It prevents devices from trying to communicate with the CPU at the same time by "interrupting" and temporarily stopping the CPU to deal with a particular request.


A telecommunication standard that allows a channel to carry voice and data in digital form over a single line.

ISP (Internet service provider)

A host computer that users can dial into over a modem to connect to the Internet.