A - Amperes

A Frame - The first frame in the repeating five-frame 3:2 pull-down sequence. In two-field 3:2 pull-down video, it is the only frame that fully contains both fields from a single film frame. B, C, and D frames have their fields split among two video frames. A frames normally occur on timecode numbers ending with 0 or 5 when using non-drop frame timecode.

access file - A text file called qtaccess that contains information about users and groups who are authorized to view media in the directory in which the access file is stored.

Access Point - A hardware device or software used in conjunction with a computer that serves as a communication hub to wireless clients and provides the same infrastructure as a network bridge to a wired LAN.

Access - To get information from something like a disk or an information service.

Activate - To make a nonactive window active by clicking anywhere inside it.

Active Window - The frontmost window on the screen; the window where the next action will take place. The active window's title bar is highlighted.

ADB-Apple Desktop Bus - Input circuitry built into older Apple computers. The ADB port attaches the keyboard, the mouse, and other input devices, such as graphics tablets and bar code readers. ADB has been replaced by USB Universal Serial Bus technology in the current models.

ADC - Apple Display Connector carries digital video, USB, and power.

Addressing - A scheme determined by network protocols for identifying the sending device and receiving device for any given item of information on a network.

Ad-Hoc Network - An independent network that provides usually temporary peer-to-peer connectivity without relying on a complete network infrastructure, which includes one or more access points.

Administrator Computer - A Mac OS X computer onto which you have installed the server applications from the Mac OS X Server Admin CD.

Administrator - When you set up Mac OS X, you set up a user. This user is an administrator. As an administrator you can create other users, including other administrators, install software in the Applications and Library folders, and change your computer's settings.

AFP Apple Filing Protocol - A client/server protocol used by Apple file service on Macintosh-compatible computers to share files and network services. AFP uses TCP/IP and other protocols to communicate between computers on a network.

AGP-Accelerated Graphics Port. AGP is a bus style that allows the graphics card to have a dedicated bus directly to the system memory. Older PCI video cards that shared data bandwidth with all installed PCI cards as well as internal I/O controllers such as IDE, SCSI, and the like. AGP allows the graphics card to be taken off that PCI bus and put onto it's own dedicated 133 MHz data bus. AGP also introduced a new slot type allowing AGP cards to transfer data faster.

AIFF Audio File - A digital audio file that can be used by iMovie and many other applications. AIFF stands for Audio Interchange File Format.

AIM - ATA Interface Module.

AirPort-Ready - A Macintosh computer with AirPort antennae installed and a slot that accepts an AirPort Card.

AirPort - Name for Apple's wireless networking technology products. Apple AirPort wireless technology uses the industry standard 802.11 and is compatible with all WiFi-certified wireless networking equipment. AirPort-equipped Macs can connect to the same wireless networks as Windows PCs in thousands of hotel rooms, coffee shops, dorm rooms, and airports. Also, a single Mac with an AirPort card can serve as a wireless access point for up to 50 PCs.

ALE - file Acronym for Avid Log Exchange. A file format that allows film databases to be shared between different systems. See also telecine log.

AltiVec or Velocity Engine - The Velocity Engine can process data in 128-bit chunks, instead of the smaller 32-bit or 64-bit chunks used in traditional processors it's the 128-bit vector processing technology used in scientific supercomputers--except that Apple has added 162 new instructions to speed up computations. In addition, it can perform four in some cases eight 32-bit floating-point calculations in a single cycle--2-4 times faster than traditional processors.

Announced Broadcast - A method such as Automated Unicast (Announce)enabling a broadcaster to negotiate with a server to accept a broadcast.

Analog Signal - A signal that varies continuously over time rather than being sent and received in discrete intervals. Digital signal-is a signal that is sent and received in discrete intervals.

ANSI - American National Standards Institute.

API - application programming interface.

Apple (K) menu - Menu at the upper-left corner of the screen, used to open System Preferences, set Dock preferences, select a network location, open recent documents and applications, shut down and restart your computer, and log out. Apple System Profiler Application that displays the specifications, such as processor speed, hard disk capacity, and memory size, for your Mac. To open Apple System Profiler, choose About This Mac from the Apple (K) menu, then click More Info. Application menu In each application, the menu item to the right of the Apple (K) menu, named after the application. The application menu is used to access the application's preference settings and to quit the application.

Apple Desktop Bus - A port for connecting the keyboard, the Apple Desktop Bus mouse, and other Apple Desktop Bus devices to the Apple IIgs. It's called a bus because several devices can ride the same cable.

AppleScript - A scripting language with English-like syntax, used to write script files that can control your computer. AppleScript is part of the Mac operating system and is included on every Macintosh.

AppleShare File Server - A Mac OS-based computer running file server software that allows users to store and share documents, folders, and applications over an AppleTalk or TCP/IP network.

AppleShare Print Server - A Macintosh computer running software that stores documents sent to it over an AppleTalk network and manages the printing of documents on a printer.

Applesoft BASIC - The Apple II dialect of the BASIC programming language; it's built into your Apple IIgs. BASIC-Acronym for Beginners All-purpose Symbolic Instruction Code. The most popular language for personal computers; a version of it is built into your Apple IIgs.

AppleTalk - A comprehensive network system developed by Apple that runs on a variety of cable systems and protocols. It facilitates communication between network devices, such as computers, file servers, and printers, which may be a mixture of Apple and non-Apple products. Several elements make up an AppleTalk network system-AppleTalk software and AppleTalk hardware; the latter includes computing components and connectivity components. AppleTalk's design allows the inclusion of a variety of data-link and cabling methods in a network system. Data-link and cabling methods widely used include LocalTalk, EtherTalk using standard Ethernet media, and TokenTalk using token ring media.

Application - Software designed for a particular purpose, such as home finance, education, or word processing.

Application Environment - Consists of the frameworks, libraries, and services along with associated APIs necessary for the runtime execution of programs developed with those APIs. The application environments have dependencies on all underlying layers of system software. Mac OS X currently has five application environments-Classic, Carbon, Cocoa, Java, and BSD Commands.

Application Programming Interface API - A set of routines used by an application to direct the performance of procedures by the computer's operating system.

Application Technology - Used to refer to any of the components used to create or support applications. For example, Java is an application technology (a language, in this instance) that is used to create and support Java applications.

Aqua - The Mac OS X user interface, characterized by translucent windows and glowing controls.

Arrow Keys - The keys in the lower-right corner of the Apple IIgs keyboard that you can press in most applications to move the cursor insertion point in the direction indicated.

Art Application - An application for drawing.

ASCII - Acronym for American Standard Code for Information Interchange; pronounced ASK-ee. A communications code that defines the representation of letters, numbers, and punctuation marks.

ASIC-Application - specific integrated circuit.

Aspect Ratio-The ratio of an image's width to its height expressed either as two numbers width:height or as a value equal to the height divided by the width. Standard video uses 4:3 0.75 while 24P video uses 16:9 0.56. Film aspect ratios depend on the format and lenses used.

Assembly Language - A programming language very close to the language of electrical impulses that is the Apple IIgs's native tongue. Because assembly-language programs require very little translation, they can be very fast.

Asynchronous & Synchronous modes - Two connected modems can communicate in either asynchronous or synchronous mode. In asynchronous mode, both modems can send data at the same time and pause at any time. To ensure that data is not lost, extra bits -called start and stop bits - are used to frame each character sent. In synchronous mode, only one modem can send data at a time. The modem sends a continuous stream and does not stop until it is finished; the other modem cannot send until the first modem is finished. No extra bits are used to frame characters.

ATA - AT attachment.

Attribute - In Entity-Relationship modeling, an identifiable characteristic of an entity. For example, lastName can be an attribute of an Employee entity. An attribute typically corresponds to a column in a database table. A column-In a relational database, is the dimension of a table that holds values for a particular attribute. For example, a table that contains employee records might have a column titled LAST_NAME that contains the values for each employee's last name.

Audio Viewer - In iMovie, the tab with the musical note at the bottom of the screen that displays audio clips in three tracks and volume adjustment controls.

Authentication Authority Attribute - A value that identifies the password validation scheme specified for a user and provides additional information as required.

Automatic Unicast (Announce) - A method of delivering a broadcast to a streaming server in which an SDP file is automatically copied and kept current on the server. A broadcast user name and password must be created before starting such a broadcast.

Auto-Repeat - To happen again and again. The keys on the keyboard are auto-repeat keys-if you hold one down, the computer will keep generating that character automatically.

AVI (Audio Visual Interleave) - A Windows video file format.