Any collection of numbers, characters or symbols which are used by a computer. Once a computer has finished processing all the data, it then presents this as information which can be understood by a user .

Database

Software that lets you enter information into one big, structured files so that it can then be searched. For example, a database could contain all your contact names and addresses or your customer details or your record collection. Each separate entry is called a record and each individual part of a record is called a field. For example, if you have a database of names and addresses, my details would be stored on one record, with my first name in one field and surname is another.

Data Encryption Key (DEK)

Much like an actual key used for locking and re-opening doors, DEKs are used for the encryption and decoding of message text, sometimes in the form of a digital signature.

Datagram

A block of data that is "smart" enough (actually, which carries enough information) to travel from one Internet site to another without having to rely on earlier exchanges between the source and destination computers (not to be confused with a Candygram).
 

Date-time

Your PC has a tiny battery inside it that allows one area of memory to permanently store the current time and date. If you need to change this, use the Control Panel.

DECnet

The proprietary network protocol designed by Digital Equipment Corporation.

Dedicated Line

A communications line that is used solely for computer connections. If you buy an additional phone line for your modem, that's a dedicated line. There are other types of dedicated lines (such as T3s and T1s) that are used for larger network entities.

Default

The options that are used if no others are specified. For example, if you run a word processor and start typing a letter, it will use the default typeface and the default paper size and margins. You can always change these settings later.

Defragmentation

When a file is saved to disk the operating system does not necessarily save it over a continuous area. If the disk is full, it might have to split the file and save it in chunks in different places. This doesn't matter to the software or the user, but it does not make it slower to retrieve the file. If you think your hard disk is slower than it used to be a few months ago, you could well be right. The answer is to use the defragmentation utility that will reorganise your hard disk so that all the files are stored in continuous areas.

Delete key

To select text or other data and remove it from a file; to remove a file from your disk. If you delete a section of text, you can immediately undelete (using the Edit/Undelete) function. If you delete a file from your disk, you can sometime undelete it depending on your PC's setup. If you are running Windows 95, there is a Recycle Bin that stores files that have deleted for a period of time- double-click on the bin icon to see your file. In Windows 3.x you can sometimes undelete a file by using the UNDELETE command .

Desktop

In Windows 95, Desktop is the term that defines what you see on your screen when Windows first start up. The icons, status bar, Start button and the Recycle Bin are all sitting together on the Desktop. It's a rather odd concept to grasp at first, but it is probably easiest to imagine as if it were a real desk. On your desk you have folders, some open (the icons and windows), a waste bin, and a small filing cabinet (OK, it's quite a big desk!) which is the My Computer icon. The Desktop contains all these icons and objects, together with a background pattern and any windows or applications that might be open .

Desktop Icons

Icons that are displayed on the Desktop. There are two icons that are always on your Windows 95 Desktop: My Computer and Recycle Bin. If you are connected to a network, you might also see an Inbox icon which lets you send and receive messages. Any other icons are called shortcuts and provide a link to a program or to a document. You can create a shortcut to any file by highlighting the file in Explorer and clicking on the right-mouse button. You'll see a menu option that says create shortcut. For example, if you create a shortcut to a document file called Letter to Boss, this will appear on your Desktop. If you double-click on this icon Windows will start your word processor and automatically load the document.

Desktop publishing, (DTP)

The design, layout and printing if documents, books and magazines using special desktop publishing software. Desktop publishing software allows you to define the size and shape of a page, position blocks of text and pictures and manipulate the text to change its size, colour, typeface, leading and alignment.

Dialup

A widely used method of accessing the Internet. A dialup connection uses regular phone lines to connect one computer to another via modem.

Digital

Used in computerese to describe information that can be represented by a collection of bits.

Digital Cameras

Cameras that do not use photographic film. The light images are converted into computer data by special electronics and are stored in memory chips within the cameras. The images can be transferred to computers and used by application programs, such as web editors and browsers.

DIR

A DOS command that displays the files stored in the current directory.

Directory 

In DOS, a way of organising files on a disk. A directory can contain files or other sub-directories. A good way of thinking of directories is to imagine a filing cabinet: the cabinet is the disk. Each drawer a directory. If you open a directory, you'll see lots of folders which are sub-directories. Look in a folder and you will see documents or files .

Disk

A flat, circular piece of plastic that's coated with a substance that is capable of being magnetised and so store information. A hard disk contains of several rigid plastic disks arranged in parallel; a floppy disk has one thin; flexible plastic disk. The disk spins at high speed and data is written to or read from the surface of the disk by a magnetic head much like the one in a cassette recorder that moves across the surface of the disk.

Disk tools

These aren't spanners! Instead, disk tools are a set of software programs that help you monitor the performance of your disk, maintain it, and ensures that it's storing data efficiently and is in tip-top condition. If you look in the Accessories folder of Windows 95, you'll see the disk tools that are provided: Disk Defragmentor will gather up data that's spread up all over the surface of your disk and store it neatly; Scan Disk will look at every part of the disk and check it for faults and, if it finds any, will try to fix them. You should run both of these tools around once a month to prevent any problems .

Display adapter

The electronic device that controls what you see on your monitor. The display adapter takes instructions from the PC and converts them into electrical signals that define the colour and character shapes you see on your screen. If you have a graphics display adapter -such as an SVGA adapter -fitted in your PC, then this will manage all the high-resolution graphics and colour and characters that you see on the monitor.

Dither

1) To smooth out any jagged edges of a curve (for example, in drawing or on a character) by placing shaded pixels between the pixels that make up the curve. Some graphics programs will do this automatically and some high-resolution laser printers will do this to improve the quality of the print.

2) To create a new colour by displaying a pattern of coloured pixels that appears, to the eye, as a new colour. The eye blends the tiny pixels together and is fooled into thinking that this is a new colour. For example, a pattern of black and white pixels equally spaced would appear as grey; increase the number of black pixels and the grey darkens.

Domain

A "logical" region of the Internet. People sometimes refer to them loosely as "sites." Generally, a domain corresponds to an IP address or an area on a host.

DOS

This was the standard, most common operating system before Windows arrived. Basically, DOS is just a piece of software that manages how files are stored on the disk. It keeps track of where the files are stored, how big they are, and when they are created. It also provides time and date functions, together with the ability to start other software programs. DOS is controlled through a command-line interface, which meansthat you have to type in words to get it to do something. For example, if you want to see the files stored on a disk, type DIR (short for directory). DOS is flexible and quick, but is difficult for beginners to use because it's not in the least bit friendly. Windows changes all this by getting rid of the command-line interface and providing a graphical user interface in which you control actions by pointing and clicking with a mouse- there's no need to learn or type in command words .

Download

To transfer information from an on-line network onto a user's personal computer. This may be done for conference or e-mail messages which need to be printed, copied to diskette, or simply browsed at leisure.

Drag and drop 

A feature of Windows (and other graphical operating systems including Apple System 7, IBM OS/2 and Unix/X). The system means you can move a highlighted icon or piece of text. For example, if you want to delete a file from the Windows 95 desktop, you move the printer to the file's icon, click once to highlight the icon, and then press and hold down the left-hand mouse button. You have now picked up the icon and can move it around the desktop. With the mouse button still pressed down, move it on top of the Recycle Bin icon. The Recycle Bin icon will change colour to indicate that it's recognised you want to use it. Now release the mouse button and you've deleted the file using drag and drop .

Driver

A special piece of software that sits between Windows and a peripheral and translates the instructions from Windows into a form that the peripheral can understand. In DOS, before Windows 95 arrived, all drivers were loaded when the PC was first switched on from within the CONFIG.SYS file, which is why your screen flashes between text and graphics mode when you first switch on your PC and it loads Windows 95.

Drop-down menu

A list of options that is displayed beneath a menu bar when you select a particular menu option. For example, if you select the File menu from any Windows application, a list of further options is displayed beneath the word file. This is a drop-down menu .

Used in computerese to describe information that can be represented by a collection of bits.

Digital Cameras

Cameras that do not use photographic film. The light images are converted into computer data by special electronics and are stored in memory chips within the cameras. The images can be transferred to computers and used by application programs, such as web editors and browsers.

DIR

A DOS command that displays the files stored in the current directory.

Directory 

In DOS, a way of organising files on a disk. A directory can contain files or other sub-directories. A good way of thinking of directories is to imagine a filing cabinet: the cabinet is the disk. Each drawer a directory. If you open a directory, you'll see lots of folders which are sub-directories. Look in a folder and you will see documents or files .

Disk

A flat, circular piece of plastic that's coated with a substance that is capable of being magnetised and so store information. A hard disk contains of several rigid plastic disks arranged in parallel; a floppy disk has one thin; flexible plastic disk. The disk spins at high speed and data is written to or read from the surface of the disk by a magnetic head much like the one in a cassette recorder that moves across the surface of the disk.

Disk tools

These aren't spanners! Instead, disk tools are a set of software programs that help you monitor the performance of your disk, maintain it, and ensures that it's storing data efficiently and is in tip-top condition. If you look in the Accessories folder of Windows 95, you'll see the disk tools that are provided: Disk Defragmentor will gather up data that's spread up all over the surface of your disk and store it neatly; Scan Disk will look at every part of the disk and check it for faults and, if it finds any, will try to fix them. You should run both of these tools around once a month to prevent any problems .

Display adapter 

The electronic device that controls what you see on your monitor. The display adapter takes instructions from the PC and converts them into electrical signals that define the colour and character shapes you see on your screen. If you have a graphics display adapter -such as an SVGA adapter -fitted in your PC, then this will manage all the high-resolution graphics and colour and characters that you see on the monitor.

Dither

1) To smooth out any jagged edges of a curve (for example, in drawing or on a character) by placing shaded pixels between the pixels that make up the curve. Some graphics programs will do this automatically and some high-resolution laser printers will do this to improve the quality of the print.

2) To create a new colour by displaying a pattern of coloured pixels that appears, to the eye, as a new colour. The eye blends the tiny pixels together and is fooled into thinking that this is a new colour. For example, a pattern of black and white pixels equally spaced would appear as grey; increase the number of black pixels and the grey darkens.

Domain

A "logical" region of the Internet. People sometimes refer to them loosely as "sites." Generally, a domain corresponds to an IP address or an area on a host.

DOS

This was the standard, most common operating system before Windows arrived. Basically, DOS is just a piece of software that manages how files are stored on the disk. It keeps track of where the files are stored, how big they are, and when they are created. It also provides time and date functions, together with the ability to start other software programs. DOS is controlled through a command-line interface, which meansthat you have to type in words to get it to do something. For example, if you want to see the files stored on a disk, type DIR (short for directory). DOS is flexible and quick, but is difficult for beginners to use because it's not in the least bit friendly. Windows changes all this by getting rid of the command-line interface and providing a graphical user interface in which you control actions by pointing and clicking with a mouse- there's no need to learn or type in command words .

Download

To transfer information from an on-line network onto a user's personal computer. This may be done for conference or e-mail messages which need to be printed, copied to diskette, or simply browsed at leisure.

Drag and drop 

A feature of Windows (and other graphical operating systems including Apple System 7, IBM OS/2 and Unix/X). The system means you can move a highlighted icon or piece of text. For example, if you want to delete a file from the Windows 95 desktop, you move the printer to the file's icon, click once to highlight the icon, and then press and hold down the left-hand mouse button. You have now picked up the icon and can move it around the desktop. With the mouse button still pressed down, move it on top of the Recycle Bin icon. The Recycle Bin icon will change colour to indicate that it's recognised you want to use it. Now release the mouse button and you've deleted the file using drag and drop .

Driver

A special piece of software that sits between Windows and a peripheral and translates the instructions from Windows into a form that the peripheral can understand. In DOS, before Windows 95 arrived, all drivers were loaded when the PC was first switched on from within the CONFIG.SYS file, which is why your screen flashes between text and graphics mode when you first switch on your PC and it loads Windows 95.

Drop-down menu 

A list of options that is displayed beneath a menu bar when you select a particular menu option. For example, if you select the File menu from any Windows application, a list of further options is displayed beneath the word file. This is a drop-down menu .