D

.dat file: A file system file.
database volume: A file that contains all of the data that is necessary for a database. A database volume can be up to 16 MB.
database synchronization: The process of bringing two separate copies of a database into agreement.
database system application programming interface: A set of functions that enable you to create and manipulate Windows CE databases. Each database consists of an arbitrary number of records, and each record consists of at least one property.
database type identifier: A user-specified token, or number, that is attached to a database. The token can be used to identify related databases by associating the same value, or related values, with each database.
datagram: A data packet, containing sufficient delivery information, that can be routed through a packet-switching network without reliance on exchanges between the source and destination computer.
data link: A connection between any two devices capable of sending and receiving information, such as a computer and a printer or a main computer and a terminal. Sometimes the term is extended to include equipment, such as a modem, that enables transmission and receiving. Such devices follow protocols that govern data transmission.
date and time picker control (DTP): A control that displays information about dates and times, and provides users with an easy way to modify this information.
datum: A frame of reference for coordinates used to describe horizontal or vertical position on or near the surface of the earth.
DCC: See direct cable connection.
.db file: A database file.
DDB: See device-dependent bitmap.
DDE: See dynamic data exchange.
DDI: See device driver interface.
DDK: See Device Driver Kit.
DDTK: See Device Driver Test Kit.
dead key: A key used with another key to create an accented character. A dead key, when pressed, produces no visible character, but indicates that the accent mark it represents is to be combined with the character produced by the next letter key pressed.
debugger window: A window that displays debugging information for an application. Examples include the Output window, the Watch window, and the Variables window.
debug configuration: A project that it is built with full symbolic debugging information and without optimization. The debug configuration is necessary for debugging. See symbolic debugging information.
debug serial port: An I/O channel that is used for debugging a device driver or platform. The debugging information is transmitted one bit at a time over a single wire.
Debug shell (Shell.exe): An interface to communicate with Cesh.exe on a development workstation.
debug zone mask: A named bit mask in application source code that is used to turn a debug zone on or off.
decryption: The process of returning encrypted data to its original form.
de-emphasis: Resets the signal magnitude on an audio channel. Compare pre-emphasis.
.def file: A module definition file. A .def file is used to export functions from a .dll file. Makefile.def is the file that contains rules that describe how to compile source code or link object modules to create a Windows CE project.
dependency: A resource on which another resource depends. If resource A depends on resource B, then B is a dependency of A.
dependency line: A .mak file entry that specifies one or more targets and zero or more dependents.
derived session key: A session key created by an application as needed. Before creating a derived session key, an application prompts the user for a password.
description block: The commands that run if the dependency is not current. Also called an inference rule.
deserialize: The process of converting a series of bytes back into an object. Compare serialize.
desktop: An on-screen work area that uses icons and menus to simulate the top of a desk. Its intent is to make a computer easier to use by enabling users to move pictures of objects and to start and stop tasks in much the same way as they would if they were working on a physical desktop.
desktop connectivity: The services required to connect a Windows CE–based device to a desktop computer.
desktop provider module: One of two DLLs that comprise a service provider. The desktop provider module handles the bulk of communication with the service manager and implements two COM interfaces. See also service provider and service manager.
development workstation: The PC-based computer on which you install Windows CE development toolkits and develop software for your Windows CE–based platform.
device: 1. A generic term for a computer subsystem. Printers, serial ports, and disk drives are often referred to as devices; such subsystems frequently require their own controlling software, called device drivers. 2. A hardware feature that can—or must—be part of the target platform. For example, a built-in device could be a low-battery notification LED, while a PC Card modem is an installable device. See also device driver.
device context: A GDI structure containing information that governs the display of text and graphics on a particular output device. A device context stores, retrieves, and modifies the attributes of graphic objects and specifies graphic modes. The graphic objects stored in a device context include a pen for line drawing, a brush for painting and filling, a font for text output, a bitmap for copying or scrolling, a palette for defining the available colors, and a region for clipping.
device-dependent bitmap (DDB): An array of bits that can only be used with a particular display or printer.
device driver: A software component that permits a computer system to communicate with a device. In most cases, the driver also manipulates the hardware in order to transmit the data to the device. However, device drivers associated with application packages typically perform only the data translation; these higher-level drivers then rely on lower-level drivers to actually send the data to the device. Many devices will not work properly—if at all—without the correct device drivers installed in the system.
device driver interface (DDI): 1. The interface between applications and the device drivers. 2. A set of functions implemented in the model device driver and called by the Graphics, Windowing, and Events Subsystem (GWES).
Device Driver Kit (DDK): A set of tools and libraries that enable programmers to write Windows-based software used to run hardware devices such as printers.
Device Driver Test Kit (DDTK): A set of tools and libraries that enable you to test the porting of your device drivers to the Windows CE operating system.
device-independent bitmap (DIB): An array of bits combined with several structures that specify the width and height of the bitmap image (in pixels), the color format of the device with which the image was created, and the resolution of the device used to create that image. A DIB generally has its own color table, and can therefore be displayed on a variety of devices.
Device Manager: An application, included on all Windows CE–based platforms, that manages stream interface device drivers. The device manager handles loading and unloading stream interface device drivers, identifying the correct driver for plug-and-play devices, managing running device drivers, and notifying stream interface device drivers of power-up and power-down events.
device partnership: A device partnership is a registry key on a Windows CE device that a desktop computer uses to identify a Windows CE device to which a desktop computer is connected. The key defines values for synchronization, file conversions, and backup and restore information, which enable multiple Windows CE devices to connect to the same desktop computer. A device partnership is created the first time you connect a Windows CE device to a desktop computer.
device provider module: One of two DLLs that comprise a service provider. The device provider module handles communication between the service manager and the device. See also service provider and service manager.
DHCP: See Dynamic Host Configuration Protocol.
dialog box: A temporary window that contains controls. You can use it to display status information and to get user input.
dialog box procedure: An application-defined callback function that the system calls when it has input for a dialog box or has tasks for a dialog box to carry out.
dialog box template: A binary description of a dialog box and the controls it contains. You can create this template as a resource to be loaded from the application's executable file, or created in memory while the application runs.
dialog editor: A resource editor that allows you to create and edit dialog boxes.
dialog unit (DLU): A unit of horizontal or vertical distance within a dialog box. A horizontal DLU is the average width of the current dialog box font divided by 4. A vertical DLU is the average height of the current dialog-box font divided by 8.
dial-up boot loader (DUB): A tool for upgrading a version of an operating system on a target device.
dial-up boot loader (DUB) boot code: System code that runs when the target device boots. The code can determine whether to boot into the target device operating system or the dial-up boot loader operating system.
dial-up boot loader (DUB) operating system: Part of the Windows CE operating system that includes code for downloading and installing an operating system image and programming the operating system image to flash memory.
Dial-Up Networking: A Windows CE–based application that enables remote users to connect to a network.
DIB: See device-independent bitmap.
digital signature: Binary data attached to a message that uniquely identifies a sender. A digital signature can be used with hash values to ensure that a transmitted message has not been tampered with.
direct cable connection (DCC): A RAS networking connection between two computers, or between a computer and a Windows CE–based device, which uses a serial or parallel cable directly connected between the systems instead of a modem and a phone line.
direct memory access (DMA): Memory access that does not involve the microprocessor and is frequently used for data transfer directly between memory and an "intelligent" peripheral device, such as a disk drive.
dirs file: A file that lists the subdirectories which contain source code or additional dirs files. Build.exe uses a dirs file to determine which subdirectories have source code that needs building.
discrete speech recognition: Speech recognition that recognizes words that are delineated by pauses.
DLL: See dynamic-link library.
DLU: See dialog unit.
DMA: See direct memory access.
DNS: See Domain Name System.
dockable window: A window that can be attached to a docking area or that can float anywhere on the screen. A dockable window has two display modes: floating or docked. See floating mode, docked mode.
docked mode: One of the operational states of a dockable window or toolbar. In docked mode, a window is attached to a docking area along any of the four borders of the main Platform Builder window. A toolbar docks vertically on a vertical docking area and horizontally on a horizontal docking area. See dockable window.
document window: A framed child window that may contain source code or other text. A document window can be displayed in a cascade or tiled arrangement.
Domain Name System (DNS): A name service that resolves system names to current IP addresses and uses a tiered or hierarchical model to pass name resolutions between domains.
dotted decimal notation: The process of formatting an Internet Protocol (IP) address as a 32-bit identifier made up of four groups of numbers, with each group separated by a period. For example, 123.432.154.12.
downcast: The process of converting a base class pointer or reference to a derived class pointer or reference.
drag-and-drop: A technique for moving or copying data between applications, between windows within an application, or within a single window in an application. The user selects the data to be transferred and drags the data to the desired destination. Windows CE supports drag-and-drop operations. However, nondefault drag-and-drop operations, equivalent to right mouse button drag-and-drop operations, are not supported.
drawing mode: Defines how foreground colors are mixed with window or screen colors for pen, brush, bitmap, and text operations. See also background graphics mode.
drop-down menu: A menu that drops from the menu bar when requested and remains open without further action until the user closes it or chooses a menu item.
DTP control: See date and time picker control.
DUB: See dial-up boot loader.
dummy file filter: A means for transferring files of nonstandard or possibly unknown extensions for which no translation is necessary. Passing the file through the dummy filter keeps the No Converter Selected dialog box from appearing.
dynamic data exchange (DDE): An interprocess communication method that allows two or more applications running simultaneously to exchange data and commands.
Dynamic Host Configuration Protocol (DHCP): A TCP/IP protocol that enables a network connected to the Internet to automatically assign a temporary Internet protocol (IP) address to a host when the host connects to the network.
dynamic-link library (DLL): A set of autonomous functions that any application can use. DLLs are a set of source code modules with each module containing a set of functions.