Data Link Control (DLC)
An error-correction protocol in the Systems Network Architecture (SNA) responsible for transmission of data between two nodes over a physical link.

Datagram
A packet of data and other delivery information that is routed through a packet-switched network or transmitted on a local area network.

DDE
Dynamic Data Exchange. An interprocess communication method that allows two or more programs running simultaneously to exchange data and commands.

DDI
Device driver interface.

DDK
Driver development kit.

Default emulated LAN
A virtual network that acts like a traditional LAN.

Default gateway
The gateway used to connect to the rest of the network.

Demand paging
A method by which code and data are moved in pages from physical memory to a temporary paging file on disk.

Device class driver
In Windows 98, a driver that provides an interface between different layers of the WDM architecture.

Device node
The basic data structure for a given device, built by Configuration Manager; sometimes called devnode. Device nodes are built into memory at system startup for each device and enumerator with information about the device, such as currently assigned resources. The complete representation of all device nodes is referred to as the hardware tree.

Dial-Up Networking
A component of Windows NT and Windows 98 that makes it possible for users to connect to remote networks such as the Internet or a private network.

Digital ID
An electronic key, obtained from a certificate authority, that provides a means for proving your identity on the Internet. Also called digital certificate or authentication certificate.

DirectShow
A multimedia technology designed to play video, audio, and other multimedia streams in a variety of formats that are stored locally or acquired from Internet servers. DirectShow relies on a modular system of pluggable components called filters arranged in a configuration called a filter graph.

DirectX
A low-level API that provides user- mode media interfaces for games and other high-performance multimedia applications. DirectX is a thin layer, providing direct access to hardware services, and takes advantage of available hardware accelerators and emulates accelerator services when accelerators are not present.
Distributed Component Object Model (Distributed COM) Additions to the Component Object Model (COM) that facilitate the transparent distribution of objects over networks and over the Internet.

Distributed computing
Information processing in which computing tasks are divided into two parts, one running on the client computer, the other on the server.

Distribution media format (DMF)
A special read-only format for 3.5-inch floppy disks that permits storage of 1.7 MB of data.

DIX
Digital/Intel/Xerox.

DLL
See dynamic-link library.

DNS
See Domain Name System.

Dock
To insert or remove a device in a computer system.

Docking station
A base unit into which you can insert portable hardware and that includes drive bays, expansion slots, and additional ports.

Domain Name System (DNS)
The naming service used on the Internet to provide standard naming conventions for IP computers.

Dotted decimal notation
A method of signifying IP addresses in which each set of eight bits is separated from the next eight bits by a period.

Drive Parameter Block (DPB)
Identical to the BIOS Parameter Block, except that it is in memory. Applications should access the DPB instead of the boot sector for logical drive information. Proper programming guidelines have always stated that applications should go through the operating system for information instead of going to the hardware itself.

DVD
Digital Versatile Disk. Optical disk storage that encompasses audio, video, and computer data.

Dynamic Host Configuration Protocol (DHCP)
An industry-standard (TCP/IP) protocol that assigns Internet Protocol (IP) configurations to computers. The DHCP-server computer makes the assignments, and the client computer calls the server computer to obtain the address.

Dynamic HTML
A collection of features that extends the capabilities of traditional HTML, giving Web authors more flexibility, design options, and creative control over the appearance and behaviour of Web pages.

Dynamic-link library (DLL)
An API routine that user-mode applications access through ordinary procedure calls. The code for the API routine is not included in the user's executable image. Instead, the operating system automatically modifies the executable image to point to DLL procedures at run time.