D

A B C D E F G H I J K L M N O P Q R S T U V W X Z

DAA – data access adapter a telephone line interface.

DAC – digital-to-analog converter.

Daisy Wheel Printer – A type of printer that produces professional-looking, letter-quality documents.

Daisy-Chaining – Stringing external devices together in a series. SCSI, USB, and FireWire technologies all allow such linking of devices in most cases.

Darwin – The core Mac OS X operating system, integrating Mach 3.0, operating-system services based on 4.4 BSD Berkeley Software Distribution, high-performance networking facilities, and support for multiple integrated file systems.

Data Base Application – A type of application that helps you keep track of lists of information. It makes it easy to recall, update, and cross-reference information.

Data Bits – The form in which the computer sends and receives information as a string of bits.

Data Compression – Data compression is the process by which data is reduced in size when it is sent from your computer to your modem, and then expanded to its original size by the receiving modem. Since the transmitted data has been compressed, it takes less time to send.

Data Disk – A disk that contains your work letters, budgets, pictures, and so on.

Data Rate – Amount of information per second.

Database Server – A data storage and retrieval system. Database servers typically run on a dedicated computer and are accessed by client applications over a network.

Database – An electronic list of records that can be sorted and/or searched.

Data – Information, especially raw or unprocessed information. Plural of datum. Information processed by a computer.

dB – Decibels.

DB9 Serial Port – Rack-mounted servers typically have a DB9 serial port, which gives system administrators a way to access a server remotely through a serial console session even if the network is down.

DCD – Stands for Data Carrier Detect. A handshake signal used to regulate the flow of data between the computer and a peripheral device.

DCE

Data Communication Equipment – Data Communication Equipment DCE is the modem connected to your computer. The DCE speed is the speed of data transfer between the modem and the telephone line. The DCE speed is also called the line speed.

DDR – Stands for Double Data Rate, and it’s used to describe memory that transfers data twice per clock cycle, theoretically yielding twice the data transfer rate of standard SDRAM.

Default – A value or setting that a device or program automatically selects if you do not specify a substitute. For example, word processors have default margins and default page lengths that you can override or reset. You can select the default action by pressing Return or Enter. The default action in a Mac OS 9 dialog is usually represented by the button with a double outline. The default action in Mac OS X is represented by the button that is pulsing.

Defragmentation – Arranging fragments of data into contiguous blocks in RAM or storage memory also called optimizing.

Delete – A key that you can press in some applications to erase the character to the left of the cursor.

Desk Accessory – A mini-application that you can use without leaving your main application.

Device Control – Technology that allows Final Cut Pro to control an external hardware device, such as a video deck or camera.

Device – A device that is connected to the computer, like a printer or a modem.

DHCP Dynamic Host Configuration Protocol-A protocol used to distribute IP addresses to client computers. Each time a client computer starts up, the protocol looks for a DHCP server and then requests an IP address from the DHCP server it finds. The DHCP server checks for an available IP address and sends it to the client computer along with a lease period-the length of time the client computer may use the address.

Dial-In Service – A network service that enables users to access network resources, such as printers and file servers, from a remote location via a modem.

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

DV (digital video) – A digital tape-recording format using approximately 5:1 compression to produce Betacam quality on a very small cassette.

Digitize – Converting linear analog data into digital data which can be used by a computer.

Digitizer – A peripheral device that takes a photo and converts the image into a form that the computer can process, save on a disk, display on the screen, or print.

DIMM – Dual Inline Memory Module.

Direct Delivery – A type of electronic mail system in which messages are sent directly from one computer to another.

Direct Sequence Spread Spectrum DSSS – A radio frequency-based transmission method defined by the IEEE 802.11 wireless LAN standard that uses a radio transmitter to spread data packets over a fixed range of the frequency band being used.

Direct to Java Client Assistant – A tool used to customize a Direct to Java Client application.

Direct to Java Client – A WebObjects development approach that can generate a Java Client application from a model.

Direct to Web Assistant – A tool that used to customize a Direct to Web application.

Direct to Web Template – A component used in Direct to Web applications that can generate a web page for a particular task for example, a list page for any entity.

Direct to Web – A WebObjects development approach that can generate a HTML-based Web applications from a model.

Direct-Connect Modem – A modem that you plug directly into a phone jack. The advantage of a direct-connect modem over an acoustic-coupler modem is that the phone signals don’t have to travel through the handset, so there’s less distortion. An acoustic-coupler modem-is a type of modem with a cradle that uses a standard telephone handset for transmission.

Directory Domain Hierarchy – A way of organizing local and shared directory domains. A hierarchy has an inverted tree structure, with a root domain at the top and local domains at the bottom.mdirectory node-See directory domain.

Directory Domain – A specialized database that stores authoritative information about users and network resources; the information is needed by system software and applications. The database is optimized to handle many requests for information and to find and retrieve information quickly. Also called a directory node or simply a directory.

Directory Services – Services that provide system software and applications with uniform access to directory domains and other sources of information about users and resources.

Directory – A list of all the files on a disk. Sometimes called a catalog. A subdirectory-is a directory within a directory that usually contains related documents; used to organize the information on large-capacity disks.

Disk Drive Controller Card – A circuit board that provides a connection between the Apple IIgs and one or two disk drives.

Disk Drive Light – A light that comes on when your disk drive is loading from or storing on a disk. Sometimes called an in-use light. When the light is off, it’s safe to put disks in or take disks out. When the light is on, don’t remove the disk inside.

Disk Drive – A device that loads information from a disk into the memory of the computer and saves information from the memory of the computer onto a disk.

Disk Image – A file that when opened using Disk Copy creates an icon on a Mac OS desktop that looks and acts like an actual disk or volume. Using NetBoot, client computers can start up over the network from a server-based disk image that contains system software.

Disk – A platter made of magnetic or optically etched material on which data can be written.

Display PostScript – The graphic device interface implemented in Mac OS X. It is the most common display system of UNIX systems, and has the advantage of being able to spool the screen display directly to a PostScript printer, unlike Windows systems and Mac OS systems earlier than Mac OS X, which have to translate the screen display through the use of printer drivers.

Display – A general term to describe what you see on your screen when you’re using a computer.

Distributed File Sharing – A type of file service in which users can share the content of their hard disks with other users on the network. Centralized file service-is a file service that is provided by a central server accessed by network users.

DMA – Stands for Direct Memory Access, in which a computer’s subsystems can directly access memory without going through the system’s main processor. This translates to a performance advantage for a computer that uses direct memory access.

DNS Domain Name System – A distributed database that maps IP addresses to domain names. A DNS server, also known as a name server, keeps a list of names and the IP addresses associated with each name.

Dock – A row of icons at the bottom of your screen. The Dock gives you instant access to the things you use most. You use the Dock to organize documents, applications, websites, servers, folders, and more. The Dock combines and adds to the functionality of the Windows Start menu and Taskbar.

Document – Information you create with a computer program. It could be a memo, a picture, a budget. Also called a file.

DOS 3.2 – Stands for Disk Operating System. An early Apple II operating system; 3.2 is the version number.

DOS 3.3 System Master – A disk that used to be packed with 5.25-inch disk drives. It performed some of the functions now handled by the Apple IIgs System Disk. It has programs for initializing disks, for copying DOS 3.3-based applications and documents, and more.

DOS 3.3 – One of three operating systems used by the Apple IIgs; 3.3 is the version number.

Dot Matrix Printer – A type of printer that forms characters with patterns of dots.

Double-Click – To position the pointer where you want an action to take place, and then press and release the mouse button twice in quick succession without moving the mouse.

Double-High Resolution – A graphics mode that can display information using a rectangular array of 560 horizontal by 192 vertical dots for black and white and 140 horizontal by 192 vertical dots for 16 colors.

Down Arrow – A key that you can press in some applications to make the cursor move down one line.

Downconverted Video – Video created by converting high definition video such as 24P to standard definition video NTSC or PAL.

Download – Transferring data from one computer to another. Downloading is receiving; uploading is sending.

DPI – Dots per inch; the number of dots that can be placed horizontally and vertically. This is also known as printer resolution.

Drag-To position the pointer on something, press and hold the mouse button, move the mouse, and release the mouse button. When you release the mouse button, you either highlight a selection or move an object to a new location.

Drill-and-Practice Application – A type of educational application that presents information, tests your retention of the material, and gives feedback based on your answers.

Drive Number – An application might ask you to distinguish between disk drives by number. Drive 1 is the drive of its type connected closest to the computer or to the connector labeled Drive 1 on a disk drive controller card. Drive 2 is the drive of its type connected to drive 1 or to the connector labeled Drive 2 on a disk drive controller card.

Driver – A file that tells a computer how to communicate with a peripheral such as a CD-ROM drive or printer.

Drop Box – A shared folder with privileges that allow other users to write to, but not read, the folder’s contents. Only the owner has full access. Drop boxes should only be created using AFP. When a folder is shared using AFP, the ownership of an item written to the folder is automatically transferred to the owner of the folder, thus giving the owner of a drop box full access to and control over items put into it.

Drop Frame Timecode – NTSC timecode that skips ahead in time by two frame numbers each minute, except for minutes ending in 0, so that the end timecode total agrees with the actual elapsed clock time. Timecode numbers are skipped, but actual video frames are not skipped. This skipping corrects for NTSC’s actual frame rate of 29.97 fps. It corrects for an inaccuracy of 3 seconds and 18 frames per hour in comparison to actual elapsed time when non-drop frame timecode is used. To avoid confusion, drop frame timecode should be avoided in film-based productions.

Dropped Frames – Frames that are not captured. If computer performance is impeded or if the scratch disk is not fast enough, frames may be dropped during the capture process. When a frame is dropped during capture, the frame before it is repeated. Dropped frames can result in an incorrect cut list and interfere with the reverse telecine process.

DSL – Digital Subscriber Line.

DSR – Stands for Data Set Ready. A handshake signal used to regulate the flow of data between the computer and a peripheral device.

DSSS – Direct Sequence Spread Spectrum, a type of modulation used in wireless networks

DTE Data Terminal Equipment – Data Terminal Equipment DTE is the computer to which your modem is connected. The DTE speed is the speed of data transfer between your computer and your modem.

DTR Data Terminal Ready – A Data Terminal Ready DTR signal is sent by the computer to the modem to indicate that the computer the data terminal is ready to communicate with the modem. DTR can also be used for other purposes, such as signaling the modem to hang up the phone called hardware hangup.

Dual System Production – Any production using separate devices to record the image and the audio. Always used in film productions and often used in 24P productions. Also known as double system production.

Dupe List – A film list Cinema Tools users can export, which indicates duplicate uses of the same film source material in an edited program.

Duration – The total running length of a video clip or other media element.

DV Format – DV is a digital video format. Common formats such as 8mm, Hi8, VHS, and SVHS are analog formats. DV differs from analog formats because it stores all video and audio information as data in a digital form. Analog is an electronic signal that loses strength every time the video is copied from one medium to another. With the DV format, there is no loss of quality when video is copied between the DV device and computer. When video is captured to a computer, edited, then exported back to tape, the quality of the original footage is retained.

DVD – Digital Versatile Disc or Digital Video Disc

DVD-R and DVD-RW DVD-R is a single-writeable format (similar in nature to CD-R). DVD-RW is a rewriteable format (similar in nature to CD-RW). DVD-RW has a read-write capacity of 4.7 gigabytes per side. It can be rewritten up to about 1000 times. Both DVD-R and DVD-RW were developed and approved by the DVD Forum (http://www.dvdforum.org), of which Apple is a member. Once written, DVD-R and DVD-RW discs can be used in many different drives and players. Check with the manufacturer of, or consult the documentation which came with, your player to find out if it is compatible with DVD-R media.

DVD+RW – A rewriteable format of similar capacity to DVD-RW, but was developed separately by the DVD+RW Alliance (http://www.dvdrw.com/).

DVD-RAM – Digital Versatile Disc-Random Access Memory. A high storage capacity, writable version of DVD technology good for backing up hard disk data.

DVD-ROM – Short for digital versatile disc or digital video disc, a new type of CD-ROM that holds a minimum of 4.7GB gigabytes, enough for a full-length movie. Often shortened to DVD. The DVD specification supports discs with capacities of from 4.7GB to 17GB and access rates of 600KBps to 1.3 MBps. One of the best features of DVD drives is that they are backward-compatible with CD-ROMs. This means that DVD players can play earlierCD-ROMs as well as later DVD-ROMs. Newer DVD players can also read CD-R discs.

DVI – Digital Visual Interface. DVI is a technology developed by a consortium of companies that enables a system to store and display moving video images. A DVI connector is more advanced than a standard VGA connector. With DVI all content transferred over the interface remains in the loss-less digital domain from start to finish for high-quality digital images.

Dvorak Keyboard – A keyboard layout designed to increase typing speed and efficiency by locating the keys used most often in the home row. Also called the American Simplified Keyboard.

Dynamic Element – A dynamic version of an HTML element. WebObjects includes a list of dynamic elements with which you can build your component.

Dynamic IP Address – An IP address that is assigned for a limited period of time or until the client computer no longer needs the IP address.

Dynamic IP – With dynamic addressing, a device can have a different IP address every time it connects to the network. Dynamic addressing simplifies network administration because the software keeps track of IP addresses rather than requiring an administrator to manage the task. This means that a new computer can be added to a network without the hassle of manually assigning it a unique IP address. Many ISPs use dynamic IP addressing for dial-up users.

Dynamic Node ID Assignment – The AppleTalk addressing scheme that assigns node IDs dynamically, rather than associating a permanent address with each node. Dynamic node ID assignment facilitates adding and removing nodes from the network by preventing conflicts between old node IDs and new node IDs.