DACL — Acronym for discretionary access control list. See discretionary access control; SACL.

Daemon — A networking program that runs in the background.

Daily backup — Copies all selected files that have been modified the day the daily backup is performed.

DARPA — Department of Defense [DoD] Advanced Research Project Agency.The US Department of Defense agency who provided the support for TCP/IP because it needed a suite of protocols that would allow communication between dissimilar computers for its network called the ARPANET (Advanced Research Project Agency NETwork).

Data carrier — In communications, either a specified frequency that can be modulated to convey information or a company that provides telephone and other communications services to consumers.

Data Communication Equipment (DCE) — In the RS232 specification a module, such as a modem, which is used to connect a DTE to other equipment. A repeater connected to a terminal or workstation for OMEGA LOCAL management use is wired as a DCE.

Data fork — The part of a Macintosh file that holds most of the file’s information, the series of bytes which makes up the actual file's data.. The data fork is the part of the file shared between Macintosh and PC clients.

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. It is nearly obsolete as a network transport protocol, but it is often used to connect PCs to HP printers.

Data Link Layer — OSI layer that handles physical link transmission errors and controls the flow of data across the network. This 2nd layer of the OSI model defines protocols governing data packetizing and transmission into and out of each node. This layer provides the digital interconnection of network devices and the software that directly operates these devices, such as network interface adapters.

Data Migration — The process of moving data from one storage media (server hard disk) to another (for example, tapes or optical drives).

Data Protection — A means of keeping the data in the network safe by usually maintaining duplicate file directories and by redirecting data from bad blocks to reliable blocks on the NetWare server’s hard disk.

Data Set — A set of data that can contain different items depending on which TSA (Target Service Agent) they are related to. This set of data can be manipulated by SBACKUP.

Data stream — Windows NT Network Monitor monitors the network data stream, which consists of all information transferred over a network at any given time.

Data Stripping — Data blocks are written to each drive in a disk array. For example, if there are three disks in the disk array, and you are storing a file, the first block will be written on disk one, the second on disk two, and the third block on disk three. This method provides better I/O performance because the I/O requests are not queued up behind one busy disk.

Data Terminal Equipment (DTE) — A device, usually a terminal or a computer, which a user interfaces with. It generates data for transmission. In the RS232 specification, DTE refers to virtually any module which is typically at the end of the segment. The DTE could be an Ethernet workstation, repeater, or bridge that attaches to a network.

Data Transport Protocols — Protocols that are concerned with the transmission of data across the network (routing), e.g. NetWare IPX/SPX and TCP/IP.

Database — A related set of data organized by type and purpose. The term can also include the application software that manipulates the data. The Windows NT Registry (a database itself) contains a number of utility databases such as user account and security information.

Database query — The process of extracting data from a database and presenting it for use.

Database server — Software such as Microsoft SQL Server that provides high-performance database access by splitting the DBMS function into a front-end component (where data is manipulated by users or applications) and a database-intelligent, back-end component (where data is stored, retrieved, and managed). In PC networks, the front-end component often resides on a personal computer controlled by a single user, while the back-end component resides on a high-performance PC that services requests for data submitted over the network by users.

Database services — Network services that provide centralized (server-based) data storage and retrieval to network clients.

Datagram — (1) A packet (in the internet protocols) that, because it is not carried on a virtual circuit, includes complete destination address specifications (provided by the user, not the network) along with whatever data it carries. It is a one-way construct much like a telegram. All packets sent into a packet switched network are essentially datagrams. See also packet. (2) Data Communication Equipment or Data Circuit-terminating Equipment. A device that connects a DTE to the communication channel.

DB-15 — A standardized connector with 15 pins for Ethernet transceivers.

DBMS — An abbreviation for database management system.

DCD — Acronym for Data Carrier Detect, which tracks the presence of a data carrier. See also data carrier.

DCE — Acronym for data communications equipment, an elaborate worldwide network of packet-forwarding nodes that participate in delivering an X.25 packet to its designated address, for example, a modem. See also node; packet; X.25.

DCOM — Acronym for Distributed Component Object Model. Use the DCOM Configuration tool to integrate client/server applications across multiple computers. DCOM can also be used to integrate robust Web browser applications.

DCOM Configuration tool — A Windows NT Server Utility that can be used to configure 32-bit applications for DCOM communication over the network. See also DCOM.

DCONFIG — A NetWare 3.1x command used to change the IPX.COM file to match the setting on the network board.

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

Decentralized Administration — A design approach of the Directory tree’s lower layers in which each Organizational Unit (location or department) can have its own administrator. Each OU administrator can create and manage lower layers (below his/her own container) independently.

Decision tree — A geographical representation of a filter’s logic used by Windows NT Network Monitor. When you include or exclude information from your capture specifications, the decision tree reflects these specifications.

Default — A setting that is automatically assigned by a program or system until the user manually changes them.

Default Account restrict — Restrictions set with the SYSCON utility under Supervisor Options for new users. These default restrictions will be applied to newly created users (not to existing users).

Default button — In some dialog boxes, the command button that is selected or highlighted when the dialog box is initially displayed. The default button has a bold border, indicating that it will be chosen automatically if you press ENTER. You can override a default button by clicking Cancel or another command button.

Default Drive — The preferred drive that a workstation is currently using.

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

Default gateway — In TCP/IP, the intermediate network device on the local network that has knowledge of the network IDs of the other networks in the internet, so it can forward the packets to other gateways until the packet is eventually delivered to a gateway connected to the specified destination. See also gateway; network ID; packet. See gateway

Default Login Script — A login script used by the server that sets up the basic mappings for the system. This script cannot be edited.

Default network — In the Macintosh environment, this refers to physical network on which a server’s processes reside as nodes and on which the server appears to users. A server’s default network must be one to which that server is attached. Only servers on AppleTalk Phase 2 internets have default networks.

Default owner — The person assigned ownership of a folder on the server when the account of the folder or volume’s previous owner expires or is deleted. Each server has one default owner; you can specify the owner.

Default printer — The printer that is used if you choose the Print command without first specifying which printer you want to use with an application. You can have only one default printer; it should be the printer you use most often.

Default profile — See system default profile; user default profile.

Default Server — The preferred server specified in the NET.CFG file on the server you attach to when loading the NetWare Requester.

Default user — Every user profile begins as a copy of default user (a default user profile stored on each computer running Windows NT Workstation or Windows NT Server).

Default zone — The zone to which all Macintosh clients on the network are assigned by default.

Defragment — A process that remaps the data on a hard disk so that an increased number of contiguous track locations can be obtained. This process may improve performance.

Delete — To erase data that has been input to a computer.

Delete Inhibit (DI) Attr — An attribute of the file system that prevents any user from deleting the directory or file.

Delete Right — An object right to delete an object. Only a leaf object or a container object that has no subordinate objects can be deleted.

Delimiter — A character used to indicate the beginning or end of a command or of a parameter within a command.

Demand paging — A method by which code and data are moved in pages from physical memory to a temporary paging file on disk. It is a common implementation of virtual memory, where pages of data are read into memory from storage in response to page faults. See also paging and virtual memory.

Department Concentrator — A hub which provides a large number of workstation connections. The term, department concentrator, refers to multiple repeaters housed in an AT-36C8 chassis.

Dependent service — A service that requires the support of another service. For example, the Alerter service is dependent on the Messenger service. See also Alerter service; Messenger service.

DES — Acronym for Data Encryption Standard, a type of encryption (the U.S. government standard) designed to protect against password discovery and playback. Microsoft RAS uses DES encryption when both the client and the server are using RAS.

Descendent key — All the subkeys that appear when a key in the registry is expanded. A descendent key is the same thing as a subkey. See also key; subkey; Windows NT Registry.

Desired zone — The zone in which Services for Macintosh appears on the network. See also default zone.

Desktop — The "background" screen that displays after you log on to Windows in which windows, icons, menus and dialog boxes display. It is actually a folder (directory) containing access to the local storage devices and network shares. The desktop is unique to a particular user profile.

Desktop pattern — A design that appears across your desktop. You can create your own pattern or select a pattern provided by Windows NT.

Destination directory — The directory to which you intend to copy or move one or more files.

Destination document — The document into which a package or a linked or embedded object is being inserted. For an embedded object, this is sometimes also called the container document. See also embedded object; linked object; package.

Destination Server — The NetWare 4 server to which data files, bindery files, and other information are migrated from a previous NetWare version or another network operating system when upgrading to NetWare 4.

DET — Directory Entry Table. A table containing basic information about entities on the volume (i.e. files, directory trustees, directories, etc.) used by a file server to keep track of locations and changes made to files and other properties related to files.

Device — Any piece of equipment that can be attached to a network — for example, a computer, a printer, or any other peripheral equipment.

Device class driver — In Windows 95(8), a driver that provides an interface between different layers of the WDM architecture

Device contention — The way Windows NT allocates access to peripheral devices, such as modems or a printers, when more than one application is trying to use the same device.

Device driver — A program that enables a specific piece of hardware (device) to communicate with Windows NT. Although a device may be installed on your system, Windows NT cannot recognize the device until you have installed and configured the appropriate driver. If a device is listed in the Hardware Compatibility List, a driver is usually included with Windows NT. Drivers are installed when you run the Setup program (for a manufacturer’s supplied driver) or by using Devices in Control Panel. See also HCL.

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

Device Numbering — A technique to identify a device such as hard disk, to enable the device to work on the network.

Device Sharing — The shared use of central devices by users and/or software programs to efficiently use the resources.

DHCP — Acronym for Dynamic Host Configuration Protocol, which offers dynamic configuration of IP addresses and related information. DHCP provides safe, reliable, and simple TCP/IP network configuration, prevents address conflicts, and helps conserve the use of IP addresses through centralized management of address allocation. See also IP address.

DHCP Relay Agent — The component responsible for relaying DHCP and BOOTP broadcast messages between a DHCP server and a client across an IP router. See also BOOTP; DHCP.

Dialog Box — A box in which you enter information needed before a command is executed. Dialog boxes contain different types of items, such as Check boxes, List boxes, Command buttons, and Tabs. See those corresponding entries for more information.

Dial-up line — A standard dial-up connection such as telephone and ISDN lines.

Dial-Up Networking — A component of Windows NT and Windows 95(8) that makes it possible for users to connect to remote networks such as the Internet or a private network. It can be thought of as the client version of Windows NT Remote Access Service (RAS), enabling users to connect to remote networks.

Differential Backup — A backup strategy that selects only the new or modified files by the archive bit but does not clear it after saving the file. NT copies only those files created or changed since the last normal (or incremental) backup. It does not mark files as having been backed up.

Digital Data — A type of data that can take discrete values, for example, text (letters) and integers (numbers).

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

Digital Signals — A sequence of voltage pulses that may be transmitted over a wire media but not through atmosphere or space. Digital signals can only take discrete values (0 or 1, for example).

DIP (DiPolar) Switches — Devices used to configure expansion boards or the system board (motherboard).

Direct Link — A communication link method where a remote session with a file server is established from a workstation.

Directory — Now commonly referred to as a "folder", a directory is an area on a disk where files and other folders are stored. You can think of a directory as a container for these various objects. Mass storage devices have a root directory that contains all other directories, thus creating a hierarchy of directories sometimes referred to as a directory tree. With Services for Macintosh, directories on the computer running Windows NT Server appear to Macintosh users as volumes and folders if they are designated as Macintosh accessible.-See also directory tree; folder.

Directory Access Protocol (DAP) — The protocol used between a Directory User Agent (DUA) and a Directory System Agent (DSA) in an X.500 directoru system.

Directory Cache Buffers — Blocks of RAM to cache directory entry blocks. As the directory cache buffers increase, file cache buffers decrease, but both should be balanced for maximum performance.

Directory Caching — The process of copying the NetWare DET and FAT from the hard disk into file server memory (RAM).

Directory database — A database of security information such as user account names and passwords, and the security policy settings. For Windows NT Workstation, the directory database is managed using User Manager. For a Windows NT Server domain, it is managed using User Manager for Domains. (Other Windows NT documents may refer to the directory database as the "Security Accounts Manager (SAM) database.")

Directory Entry Blocks — Divisions of DET which store directory entries.

Directory Hashing — The indexing of the memory-stored DET. This indexing reduces the disk I/O response time by 30%.

Directory Map Object — A leaf object used as a pointer (reference) to a directory on a volume.

Directory Path — The full specification of a pathname including the server name, volume name, and the name of each directory leading to the file system directory to be accessed.

Directory Replication — The copying of a master set of directories from a server (called an export server) to specified servers or workstations (called import computers) in the same or other domains. Replication simplifies the task of maintaining identical sets of directories and files on multiple computers, because only a single master copy of the data must be maintained. Files are replicated when they are added to an exported directory, and every time a change is saved to the file. See also Directory Replicator service.

Directory Replicator Service — Replicates directories, and the files in those directories, between computers. See also directory replication.

Directory Rights — The rights that control what a trustee can do with a specific directory.

Directory Services — The NetWare 4 built in database which maintains the information about each resource in the network. See NDS and Windows NT Directory Services.

Directory Tree — A graphical display of a disk's directory hierarchy. The directories and folders on the disk are shown as a branching structure. The top-level directory is the root directory.

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

Dirty Cache Buffers — In MONITOR.NLM utility, it shows the number of file blocks in memory (updated data) that are waiting to be written to disk.

Disabled user account — A user account that does not permit logons. The account appears in the user account list of the User Manager or User Manager for Domains window and can be re-enabled at any time. See also user account.

Discardable code segment — A Windows application code segment in memory, which can be discarded, overwritten, or reloaded from disk when necessary.

Discovery — A process by which the Windows NT Net Logon service attempts to locate a domain controller running Windows NT Server in the trusted domain. Once a domain controller has been discovered, it is used for subsequent user account authentication.

Discretionary access control — Allows the network administrator to allow some users to connect to a resource or perform an action while preventing other users from doing so. See also discretionary access control list (DACL); SACL.

Disjoint networks — Networks that are not connected to each other.

Disk — A circular medium use to store and retrieve computer data. The most common type of disk is the magnetic disk, which is a circular platter with a magnetic coating on both sides. As the platter spins, data is written or read magnetically.

Disk Allocation Blocks — Also called Disk Blocks, it is the individual storage units within a volume. Files are stored in disk blocks.

Disk Block — A NetWare volume is divided into blocks to store files or data.

Disk cache — A part of RAM that is set aside to temporarily hold data read from disk. A disk cache doesn’t have to hold an entire file, as a RAM disk does, but can hold parts of running application software or parts of a data file. Disk-caching software such as SMARTDrive manages the process of swapping data to and from the disk cache.

Disk Channel — A disk channel consists of a disk coprocessor board (DCB), if using, disk controller, and disks attached with the controller.

Disk configuration information — The Windows NT registry includes the following information on the configuration of your disk(s): assigned drive letters, stripe sets, mirror sets, volume sets, and stripe sets with parity. Disk configuration can be changed using Disk Administrator. If you choose to create an Emergency Repair disk, disk configuration information will be stored there, as well as in the registry.

Disk Controller — A chip set on the motherboard that controls how the data is written to, and retrieved from, the disk drive.

Disk Drive — A mechanism that stores and loads files from a disk. The term drive refers to the mechanism as a whole. In addition to the disk drive, there are CD-ROM drives, Tape Drives and other media which serve a similar purpose.

Disk Driver — A software component of a NetWare that controls communication between the operating system and the hard disks.

Disk Duplexing — It is the same as disk mirroring, but it duplicates the disk channel (the disk coprocessor board (DCB), cable unit, and drive controller).

Disk Format — The way that a hard disk is structured so that it can receive data from the computer’s operating system.

Disk Mirroring — Stores duplicate data on two, same logical sized hard disks connected to the same disk channel. If one disk fails, the operating system automatically uses the other (mirrored) disk.

Disk Partition — A logical unit that NetWare server hard disks can be divided into. In NetWare, it is created on every hard disk, and the volumes are created from the pool of NetWare partitions.

Disk Subsystem — An external unit attached to the NetWare server that gives the server more storage capacity. It contains hard disks, a tape drive, optical drives, or a combination of each.

DISPLAY — A login script command to show the contents of a specified text file on your workstation screen during the login.

Display filter — Functions like a database query, allowing you to single out specific types of information. Because a display filter operates on data that has already been captured, it does not affect the contents of the Network Monitor capture buffer. See also capture buffer.

Display LIA — Display Lost Interrupt Alerts.Parameter that will send a message to the server console if a driver or board sends an interrupt to the CPU and then drops the request before CPU can respond to the request. By default, this parameter is ON.

DISPLAY NETWORKS — A console command used to list all networks that the file server router is aware of.

Display password — Required to be able to open previously saved capture (.cap) files in Network Monitor.

DISPLAY SERVERS — A console command used to list all servers that the file server is aware of.

Distance Vector — Routers using distance vector route discovery method build their Routing Information Tables based on information received from other routers (neighbor routers).

Distinguished Name — An NDS path name that includes the leaf name and all the container names up to the [Root]. It must always begin with a period Also known as Complete Name.

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 — A computing (processing) system where the processing is distributed among multiple computers. All computers have internal processing power (called intelligent clients) and process applications locally instead of relying on one central computer. (a) NetWare LANs are prime examples of the distributed computing model. When a user requests an application, file, or data from the file server, it is loaded into the client’s memory and processed using the client’s resources. (b)With NT the server side of a distributed application registers its availability with the RPC Locator service. The client side of a distributed application queries the RPC Locator service to find available compatible server applications. See also RPC.

Distributed Data System — Technology related to database services in which pieces of the database are distributed across multiple servers. This strategy increases performance because data may be available to users locally, and increases reliability because all data is not stored on a single computer.

Distributed Processing — A process whereby each workstation on the network executes its own application(s)

Distributed server system — In Windows NT, a system in which individual departments or workgroups set up and maintain their own remote access domains.

Distribution List — A leaf object that can be created to send the same message to multiple recipients.

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

DLC (Data Link Control) — Protocols governing packet information including destination address, source address, and control information.

DLL — See dynamic-link library.

DMA — An abbreviation for Direct Memory Access, which is memory access that doesn’t use the microprocessor, often used to transfer data directly between memory and a peripheral device such as a hard disk drive.

DNA — Digital Network ArchitectureThe proprietary network architecture of the Digital Equipment Corporation (DEC). The latest revision of DNA is called Phase V. It spans all seven layers of the OSI Reference Model.

DNS — Domain Name System. DNS uses a distributed database system to provide address/name resolution. Under DNS, the information is distributed among thousands of name servers organized into a hierarchy to identify devices on the Internet. See Domain Name System.

DNS name servers — In the DNS client-server model, the servers containing information about a portion of the DNS database, which makes computer names available to client resolvers querying for name resolution across the internet. See also Domain Name System (DNS).

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

Document — A self-contained file created with an application program and, if saved on disk, given a unique filename by which it can be retrieved. A document can be a text file, a spreadsheet, or an image file, for example.

Document file — A file that is associated with an application. When you open a document file, the application starts and loads the file. See also associate.

Document file icon — Represents a file that is associated with an application. When you double-click a document file icon, the application starts and loads the file. See also associate.

Document icon — Located at the left of a document window title bar, the document icon represents the open document. Clicking the document icon opens the window menu. Also known as the control menu box.

Domain — (1) In Microsoft networks, a domain is an arrangement of client and server computers referenced by a specific name that share a single security permissions database. A domain provides access to the centralized user accounts and group accounts maintained by the domain administrator(s). Each domain has a unique name. (2) On the Internet, a domain is a named collection of hosts and subdomains registered with a unique name by the InterNIC. (3) Loadable module in NetWare used to create an OS domain and an OS-PROTECTED domain to protect server memory from ill-behaved NLMs.

Domain Controllers — Servers that authenticate workstation network logon requests by comparing a username and password against account information stored in the user accounts database. A user cannot access a domain without authentication from a domain controller. Domain controllers can mirror one another and be distributed between the remote locations. This allows domain users to log on from any location. In a Windows NT Server domain, this term refers to the computer running Windows NT Server that manages all aspects of user-domain interactions, and uses information in the directory database to authenticate users logging on to domain accounts. One shared directory database is used to store security and user account information for the entire domain. A domain has one primary domain controller (PDC) and one or more backup domain controllers (BDCs). See also directory database; member server; PDC; BDC.

Domain database — See directory database.

Domain model — A grouping of one or more domains with administration and communication links between them that are arranged for the purpose of user and resource management.

Domain name — Part of the Domain Name System (DNS) naming structure, a domain name is the name by which a domain is known to the network. Domain names consist of a sequence of labels separated by periods. See also DNS; FQDN.

Domain Name Service (DNS) — The TCP/IP network service that translates textual Internet network addresses into numerical Internet network addresses.

Domain name space — The database structure used by the Domain Name System (DNS). See also DNS.

Domain Name System (DNS) — The naming service used on the Internet to provide standard naming conventions for IP computers. Sometimes referred to as the BIND service in BSD UNIX, DNS offers a static, hierarchical name service for TCP/IP hosts. The network administrator configures the DNS with a list of hostnames and IP addresses, allowing users of workstations configured to query the DNS to specify remote systems by hostnames rather than IP addresses. For example, a workstation configured to use DNS name resolution could use the command ping remotehost rather than ping 172.16.16.235 if the mapping for the system named remotehost was contained in the DNS database. DNS domains should not be confused with Windows NT networking domains. See also ping; IP address.

Domain synchronization — See synchronize.

Don’t Compress (Dc) Attr — An attribute of the file system which prevents files from being compressed.

Don’t Migrate (Dm) Attr — An attribute of the file system which prevents files from being migrated to a secondary storage device such as a tape drive or an optical disk.

Don’t Suballoc (Ds) Attr — Don't Suballocate (Ds) Attribute. An attribute of the file system which prevents a single file from being suballocated;although, suballocation is enabled for the system.

DOS — Acronym for "Disk Operating System". It is a set of small programs whose main function is to control the flow of data to and from the disk drives and other peripherals. This name has been used by several computer manufacturers for various operating systems, but is generally associated with Microsoft. Windows is a successor to DOS. See MS-DOS.

DOS BREAK ON/OFF — A login script command to terminate the execution of a program if you want to use < Ctrl > < Break >.

DOS Client — A workstation which boots with DOS and gets access to the network through either the NetWare DOS Requester software or a NetWare Shell.

DOS Directory — A directory created for each DOS version (if your users are using different versions of DOS).

DOS Extender — See extended memory manager.

DOS Requester — A group of files that provides an interface between local DOS applications and the NetWare operating system.

DOS SET — A login script command to set a DOS environment variable.

DOS VERIFY ON/OFF — A login script command to verify that the data copied to a local drive using the DOS COPY command can be read after the copy.

DOSGEN — This utility allows the DOS workstation to boot from the file server rather than from a local drive.

Dots Per Inch (DPI) — The standard used to measure print device resolution. The greater the DPI, the better the resolution.

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. Also, referred to familiarly as dotted-quad.

Double buffering — The use of two buffers rather than one to temporarily hold data being moved to and from an I/O device. Double buffering increases data transfer speed because one buffer can be filled while the other is being emptied.

Double-click — To rapidly press and release a mouse button twice without moving the mouse. Double-clicking carries out an action, such as starting an application.

Downlink — Pertaining to data transmission from a data station to the headend. For example, a hub may have an uplink to a more central hub or router.

Downloadable fonts — Fonts that reside on your hard disk and that are sent to the printer as needed.

Downloadable soft fonts — Fonts that are stored on disk and downloaded as needed to the print device.

Downloaded fonts — Fonts that you send to your printer either before or during the printing of your documents. When you send a font to your printer, it is stored in printer memory until it is needed for printing. See also font; font types.

DPI — See dots per inch.

DPMI — An abbreviation for DOS Protected Mode Interface, an industry standard that allows MS-DOS applications to execute code in the protected operating mode of the 80286 or 80386 processor. The DPMI specification is available from Intel Corporation.

Drag — To move an item on the screen by selecting the item and then pressing and holding down the mouse button while moving the mouse. For example, you can move a window to another location on the screen by dragging its title bar.

DRIVE — A login script command to specify your default drive.

Drive icon — An icon in the All Folders column in Windows NT Explorer or the Names Column in My Computer that represents a disk drive on your system. Different icons depict floppy disk drives, hard disk drives, network drives, RAM drives, and CD-ROM drives.

Drive Mapping — Assigning a letter of the alphabet to a NetWare volume or directory, so you can easily access it without typing the complete path.

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

Driver — A program that coordinates communication between a hardware device and the operating system or an application. Drivers are written for the specific device that they control, but they present a common software interface to the computer’s operating system, allowing devices of a similar type to be controlled as if they were the same. See device driver.

Drop folder — In the Macintosh environment this refers to a folder for which you have the Make Changes permission but not the See Files or See Folders permission. You can copy files into a drop folder, but you cannot see what files and subfolders the drop folder contains.

DSDM — Acronym for DDE share database manager. See also DDE; Network DDE DSDM service.

DSMERGE — A NetWare 4 loadable module used to merge the roots of two separate NDS trees.

DS-0 — A digital signal used for leased telephone lines. It is a 64Kbps channel carried within a DS-1 or E1 signal.

DS-1 — A digital standard for transferring data on leased lines. DS-1 transmits up to 1.544 Mbps and is used in North American. This standard is also called T-1, which is when this standard of signaling is delivered on twisted pair wiring. The European standard is called E-1.

DS-3 — A digital standard for transferring data on leased lines. DS-3 is the equivalent of 28 DS-1 lines, or 45 Mbps. As the transmission speed increases, the telephone company installing and maintaining the line must use more signal repeaters to keep the data signal clear and strong.

DSPACE — A NetWare 3.1x command used to limit the user's disk space on a volume and in a directory. It is also used to control maximum disk space in a directory.

DSR — Acronym for Data Set Ready signal, used in serial communications. A DSR is sent by a modem to the computer to which it’s attached to indicate that it is ready to operate. DSRs are hardware signals sent over line 6 in RS-232-C connections.

DSREPAIR — NetWare 4 NLM used at the console to repair and adjust problems in the NDS database.

DTE — Acronym for Data Terminal Equipment, for example a RAS server or client. See also Remote Access Service (RAS).

Dual boot — A computer that can boot two different operating systems. See also multiple-boot.

Duplex — Duplex refers to a network devices ability to send and receive at the same time. If a device can send and receive and the same time, it is considered full-duplex. Some devices don't support that option or don't work reliably while duplexing, so they run at half-duplex. Half-duplex is supported by all network devices.

DVD — Optical disk storage that encompasses audio, video, and computer data

DWORD — A data type composed of hexadecimal data with a maximum allotted space of 4 bytes.

Dynamic Configuration — A method that allows the NetWare server to allocate resources as needed according to the availability.

Dynamic data exchange (DDE) — A form of interprocess communication (IPC) implemented in the Microsoft Windows family of operating systems. Two or more programs that support dynamic data exchange (DDE) can exchange information and commands. See also IPC.

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 behavior of Web pages

Dynamic Memory — The form of memory commonly used for RAM. Dynamic memory requires a continuous power supply to keep the data that it is holding. If the power is turned off, all data will be lost.

Dynamic Patch — A NetWare utility that is implemented as an .NLM file which can be loaded and unloaded when the server is up. This is used to update the NetWare operating system.

Dynamic Routing — (1) Dynamic routing automatically updates the routing tables, reducing administrative overhead (but increasing traffic in large networks). See also routing table. (2) A type of routing in which the host builds up the routing table itself based on the routing information available on the network. DynaText, A NetWare 4 GUI utility that provides an electronic version of the NetWare manuals.