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

(D)

DAEMON: A daemon (pronounced DEE-muhn) is a program that runs continuously and exists for the purpose of handling periodic service requests that a computer system expects to receive. The daemon program forwards the requests to other programs (or processes) as appropriate. Each server of pages on the Web has an HTTPD or Hypertext Transfer Protocol daemon that continually waits for requests to come in from Web clients and their users.
In mythology, a daemon, according to Webster's, was "an attendant power or spirit."
Daemon can be confused with demon, which has a different but similar meaning. The New Hackers Dictionary says that a daemon is a program that runs by itself directly under the operating system whereas a demon is part of a larger application program.

DAT: DAT (Digital Audio Tape) is a standard medium and technology for the digital recording of audio on tape at a professional level of quality. A DAT drive is a digital tape recorder with rotating heads similar to those found in a video deck. Most DAT drives can record at sample rates of 44.1 KHz, the CD audio standard, and 48 KHz. DAT has become the standard archiving technology in professional and semi-professional recording environments for master recordings. Digital inputs and outputs on professional DAT decks allow the user to transfer recordings from the DAT tape to an audio workstation for precise editing. The compact size and low cost of the DAT medium makes it an excellent way to compile the recordings that are going to be used to create a CD master.
As an archival medium, DAT is an alternative to consider along with:
Digital Data Storage (DDS1 through DDS3)
Optical disk
VHS tape
DATA: The term given to raw, unprocessed bits travelling across a network in packets. Computer processing turns the data into information that we can utilise, and vice versa.
DHCP: DHCP (Dynamic Host Configuration Protocol) is a protocol that lets network administrators manage centrally and automate the assignment of Internet Protocol (IP) addresses in an organisations network. Using the Internets set of protocols (TCP/IP), each machine that can connect to the Internet needs a unique IP address. When an organisation sets up its computer users with a connection to the Internet, an IP address must be assigned to each machine.
Without DHCP, the IP address must be entered manually at each computer and, if computers move to another location in another part of the network, a new IP address must be entered. DHCP lets a network administrator supervise and distribute IP addresses from a central point and automatically sends a new IP address when a computer is plugged into a different place in the network.
DHCP uses the concept of a "lease" or amount of time that a given IP address will be valid for a computer. The lease time can vary depending on how long a user is likely to require the Internet connection at a particular location. It is especially useful in education and other environments where users change frequently. Using very short leases, DHCP can dynamically reconfigure networks in which there are more computers than there are available IP addresses.
DHCP supports static addresses for computers containing Web servers that need a permanent IP address.
DHCP is an alternative to another network IP management protocol, BOOTP (Bootstrap Protocol). DHCP is a more advanced protocol, but both configuration management protocols are commonly used. Some organisations use both protocols, but understanding how and when to use them in the same organisation is important. Some operating systems, including Windows NT, come with DHCP servers. A DHCP or BOOTP client is a program that is located in (and perhaps downloaded to) each computer so that it can be configured.

DIAL UP CONNECTION: A connection to the Internet via phone and modem. Connection types include PPP and SLIP.

DIALUP: 'Dialup Access' or a 'Dialup Account' is when a modem is used to gain access to the Internet via a network.

DIGERATI: The digital version of literati, it is a reference to a vague cloud of people seen to be knowledgeable, hip, or otherwise in-the-know in regards to the digital revolution.

DIRECT CONNECTION: A connection made directly to the Internet - much faster than a dial-up connection.

DIRECTORY: A directory is, in general, an approach to organizing information, the most familiar example being a telephone directory.
1) On the World Wide Web, a directory is a subject guide, typically organized by major topics and subtopics. The best-known directory is the one at Yahoo (http://www.yahoo.com). Many other sites now use a Yahoo-like directory including major portal sites.
2) In computer file systems, a directory is a named group of related files that are separated by the naming convention from other groups of files.
I.E: C:\
OR C:\WINDOWS\

DISCUSSION GROUP: A particular section within the USENET system typically, though not always, dedicated to a particular subject of interest. Also known as a newsgroup.

DLL: In computers, a dynamic link library (DLL) is a collection of small programs, any of which can be called when needed by a larger program that is running in the computer. The small program that lets the larger program communicate with a specific device such as a printer or scanner is often packaged as a DLL program (usually referred to as a DLL file).
The advantage of DLL files is that, because they don't get loaded into random access memory (RAM) together with the main program, space is saved in RAM. When and if a DLL file is needed, then it is loaded and run. For example, as long as a user of Microsoft Word is editing a document, the printer DLL file does not need to be loaded into RAM. If the user decides to print the document, then the Word application causes the printer DLL file to be loaded and run.
A DLL file is often given a ".dll" file name suffix. DLL files are dynamically linked with the program that uses them during program execution rather than being compiled with the main program. The set of such files (or the DLL) is somewhat comparable to the library routines provided with programming languages such as C and C++.

DNS: The domain name system (DNS) is the way that Internet domain names are located and translated into IP (Internet Protocol) addresses. A domain name is a meaningful and easy-to-remember "handle" for an Internet address.
Because maintaining a central list of domain name/IP address correspondences would be impractical, the lists of domain names and IP addresses are distributed throughout the Internet in a hierarchy of authority. There is probably a DNS server within close geographic proximity to your access provider that maps the domain names in your Internet requests or forwards them to other servers in the Internet.

DOMAIN NAME: The unique name that identifies an Internet site. Domain Names always have 2 or more parts, separated by dots. The part on the left is the most specific, and the part on the right is the most general. A given machine may have more than one Domain Name but a given Domain Name points to only one machine. For example, the domain names:
plus.net
mail.plus.net
relay.plus.net
can all refer to the same machine, but each domain name can refer to no more than one machine.
Usually, all of the machines on a given Network will have the same thing as the right-hand portion of their Domain Names (plus.net in the examples above). It is also possible for a Domain Name to exist but not be connected to an actual machine. This is often done so that a group or business can have an Internet e-mail address without having to establish a real Internet site. In these cases, some real Internet machine must handle the mail on behalf of the listed Domain name.

DOS: The first personal computer DOS, called PC-DOS, was developed for IBM by Bill Gates and his new Microsoft Corporation. He retained the rights to market a Microsoft version, called MS-DOS. PC-DOS and MS-DOS are almost identical and most users have referred to either of them as just "DOS." DOS was (and still is) a non-graphical line-oriented command-driven operating system, with a relatively simple interface but not overly "friendly" user interface. Its prompt to enter a command looks like this:
C:\>
The first Microsoft Windows operating system was really an application that ran on top of the MS-DOS operating system. Today, Windows operating systems continue to support DOS (or a DOS-like user interface) for special purposes by emulating the operating system.
In the 1970s before the personal computer was invented, IBM had a different and unrelated DOS (Disk Operating System) that ran on smaller business computers. It was replaced by IBMs VSE operating system.

DOWNLOAD: The process of copying data file(s) from a remote computer to a local computer. The opposite action is upload where a local file is copied to a server.