I/O Error Message – Stands for input/output. A message you get when there’s a problem with the way information is being exchanged with peripheral devices.

IANA – An organization responsible for allocating IP addresses, assigning protocol parameters, and managing domain names.

ICMP (Internet Control Message Protocol) – A message control and error-reporting protocol used between host servers and gateways. For example, some Internet software applications use ICMP to send a packet on a round-trip between two hosts to determine round-trip times and discover problems on the network.

Icon – A symbol like the one on the back panel of the computer that shows you where to plug in the monitor or a symbol on the screen that represents a disk, a document, or something else you can select.

IDE – integrated device electronics.

Identifier – In Cinema Tools, a combination of one or more letters, numbers, or both, that identifies a shot, scene, take, video reel, sound roll, lab roll, or camera roll.

Idle User – A user who is connected to the server but hasn’t used the server volume for a period of time.

IEEE 802.11 – The worldwide industry standard for wireless communications that allows for interoperability among 802.11-compliant equipment.

IEEE – The Institute of Electrical and Electronics Engineers, Inc., an organization dedicated to promoting standards in computing and electrical engineering.

IGMP (Internet Group Management Protocol) – An Internet protocol used by hosts and routers to send packets to lists of hosts that want to participate, in a process known as multicasting. QuickTime Streaming Server (QTSS) uses multicast addressing, as does Service Location Protocol (SLP).

IMAP (Internet Message Access Protocol) – A client-server mail protocol that allows users to access their mail from anywhere on the Internet. Mail remains on the server until the user deletes it.

Information Service – A large data base that you can subscribe to for news, stock quotes, and other services.

Infrared Technology – A communications method based on light waves that fall between visible and microwave on the optical spectrum.

Initializing – Formatting a disk for use in the computer. Initializing creates a new directory and arranges the tracks for the recording of data. Initializing erases all data on the disk.

Ink Number – A number added by the film lab to the edge of workprints and magnetic film sound tracks that can be used in conjunction with the key numbers. Also known as an Acmade number.

Input/Output – Abbreviated I/O. Refers to the means by which information is sent between the computer and its peripheral devices. Also known as I/O.

Input – Information traveling into the computer, like keypresses and mouse moves.

Insertion Point – The place where your next action will take place.

Installer – Software used to install a program on the hard disk of a computer.

Instant On – An advance in Apple’s patent-pending Skip Protection technology that dramatically reduces buffer, or wait, time for an instantaneous viewing experience with streaming video on a broadband connection.

Integrated Circuit – An electronic circuit including components and interconnections entirely contained in a single piece of semi-conducting material, usually silicon. Often referred to as a chip.

Integrated Software – A group of application programs, usually on one disk, designed to share data.

Interface Card – A circuit board you plug into one of the slots in the Apple IIgs to link the computer to a peripheral device.

Interface – Hardware or software that links the computer to a device.

Interlaced Video – A video frame format that divides the lines into two fields, each consisting of alternating odd and even lines, which are scanned at different times. Used in standard definition video.

Internationalization – The design or modification of a software product, including online help and documentation, to facilitate localization. Internationalization of software typically involves writing or modifying code to make use of locale-aware operating-system services for appropriate localized text input, display, formatting, and manipulation. Also known as localization.

Interpositive IP – A low-contrast positive film print made from an original camera negative. It is not projectable as a full-color image, since it has an orange mask on it like a negative. IPs are typically used as an intermediate step in creating opticals and duplicate negatives.

Inverse Characters – Inverse means opposite. If characters ordinarily show up as light characters on a dark screen, inverse characters would show up as dark characters on a light screen. Inverse is one form of highlighting.

IP (Internet Protocol) – A connectionless protocol used to transmit packets of data from one machine to another. TCP and UDP use IP for their host-to-host data communications.

IP Address-Internet Protocol Address – A computer’s unique Internet address such as that identifies it on a TCP/IP-protocol network. Many computers also have a domain name assigned to them, which represents IP addresses as words that are easier to remember such as, apple.com.

IP Subnet – A portion of an IP network, which may be a physically independent network segment, which shares a network address with other portions of the network and is identified by a subnet number.

IrDA – Infrared Data Association.

IR – infrared.

IrTalk – An Apple proprietary infrared communications standard. Not compatible with IrDA.

ISO – International Organization for Standardization.

ISP – Internet service provider.

ITU – The ITU International Telecommunications Union, formerly known as CCITT, is an international organization which studies telecommunications technology and recommends international telecommunications standards. These standards enable different devices from different manufacturers to communicate with each other.