| Term | Description |
| I/O Address | An address in memory that is associated with a specific device, (serial port, parallel port, expansion slot) and allows the CPU to communicate with that port or expansion slot, thus allowing communication with the device attached. |
| IBM Compatible | A term used to describe a wide array of computer systems, made by different companies, that adhere to IBM standards. |
| IC | See Integrated Circuit Chip. |
| Icon | A small graphical image or picture used to represent a program, folder, or function. Operating Systems that use a Graphical User Interface (GUI) allow you to start a program or perform file navigation and manipulation by clicking or double-clicking on these icons. |
| ICQ | An online, real-time chat program developed by Mirabilis that allows users to send and receive messages back and forth on the Internet. It can be configured to alert or notify the user when acquaintances are online. |
| Importing | To bring a file created in one application or program into another application for use in that program. |
| Inactive Window | Some Operating Systems will allow more than one window to be visible on screen at the same time. Any window that you are not currently working in is an Inactive Window. The window your are currently working in is considered the Active window. |
| Incremental Backup | Backing up only those files that have been changed since the last backup was performed. |
| Industry Standard Architecture | See ISA. |
| Initialization | Starting up, or making preparations to start up a computer system, a program, or a device by running a self-diagnostic program, or loading drivers, changing settings, and preparing it for use. |
| Initialization File | See .INI file. |
| Input | The data or information entered into a computer; or the act of entering that data into the computer. |
| Input Device | Any device that sends information into your computer system. i.e. : keyboard, scanner, mouse, trackball. |
| Input/Output Controller | I/O controllers free up the CPU by managing the communication between various input and output devices. |
| Integrated Circuit Chip | Circuits are made up of different electronic components (capacitors, resistors, transistors) wired together in a manner that performs a specific electronic function. With today's technology, these circuits can be etched into small wafers of silicon and sandwiched into a package with small metal pins protruding. These are Integrated Circuit Chips. |
| Interface | A communication link in a computer between hardware and software components. A user interface is the way a user communicates with a computer. As a verb, to interface is to communicate. |
| Interlaced | A method of refreshing the image on a monitor. Instead of refreshing the entire image (non-interlaced), an interlaced monitor refreshes the odd-numbered scan lines first, then refreshes the even-numbered scan lines on the second pass. This reduces the amount of new information that has to be passed on each sweep, but causes almost unnoticeable flicker, that can result in eye fatigue. |
| Internal Cache | A small amount of very fast RAM that is stored inside the CPU. It is faster than External or L2 cache and is referred to as L1 or Level 1 cache. |
| Internet | A global network that links millions of computers together for communication purposes. The Internet was originally developed in 1969 for the U.S. military and grew to include educational and research institutions. Today, all kinds of clients, from home users to multimillion-dollar corporations, communicate over the Internet, sharing files, information, resources and messages. |
| Internet Service Provider | See ISP. |
| Interpolated Resolution | Image resolution is measured in Dots Per Inch (DPI). Software programs have the ability to enhance an image and increase the resolution by guessing at the color of a dot in between dots of a known color. This software enhanced resolution is known as Interpolated Resolution. |
| Interrupt | An interrupt is a command sent to the processor to get its attention. The CPU then has to decide whether to continue with what its doing and handle this command later, or set aside what its doing and handle the interrupt immediately. Interrupts are prioritized and can be sent from hardware devices or software. |
| Interrupt Handler | A program (either BIOS or a device driver), that is used by the CPU to process a hardware interrupt. |
| Intranet | An Intranet is a network of computers in an office or building that communicate with each other and share files and resources such as laser printers and file storage space on servers. |
| IO.SYS | A system file for the MS-DOS operating system. Its a hidden file in the root directory of the primary partition of the primary drive. This file provides the basi I/O capabilities for the system, allowing it the ability to communicate with the different peripherals. IO.SYS directs the overall process of loading the Operating System. |
| IRQ | Interrupt Request Lines are electronic pathways that are assigned to specific devices such as modems, keyboards, mice, sound cards, etc.. These IRQs are assigned and prioritized according to the importance of each device, so that the most important interrupt requests are handled first by the CPU. |
| ISA | Industry Standard Architecture.. ISA is a 16-bit expansion bus standard that was modeled after IBM's original 8-bit PC bus. A wider bus allows for larger and faster data transfer. The 16-bit ISA slots can still be found on computers today because of the large number of ISA-compatible expansion cards still in existence. |
| ISP | An Internet Service Provider allows your computer access to their computers and Internet access for a fee. Most ISPs provide access to the Internet and the World Wide Web with one or more email addresses. You can also get Internet access through Online Service Providers such as CompuServe and America Online. They offer other features such as chat rooms, forums, and searchable databases, but are usually more expensive. |