John Cletheroe's
PC And Internet Hints

PC And Internet Glossary - Including File Extensions - E

E-Commerce

Electronic commerce. The buying of goods and services via the Internet.

E107

A CMS (Content Management System).

EAP

Extensible Authentication Protocol. PEAP is Protected Extensible Authentication Protocol, which appears to be an alternative name for the 802.1x wireless protocol.

Early Binding

Early binding takes place when a compiler for a programming language can resolve a reference to an external function, subroutine or procedure at compile time (in other words, when it can compute the machine code details of how to call it). Late binding takes place when the reference cannot be resolved until runtime. Generally, early binding results in faster program operation than late binding.

Easter Egg

A hidden feature of a program, written largely for the amusement of the programmer. Easter eggs sometimes display additional author credits, fancy graphics or other clever, amusing or self-indulgent features. When commercial programs are released without being fully de-bugged many users feel that the programmers' time would have been better spent on that task rather than on producing Easter eggs. One of the most glorious Easter eggs is a simple flight simulator in Microsoft Excel 97, a program which according to Woody's Office Watch was released with a number of fundamental bugs in its spreadsheet recalculation routines.

EBD

Emergency Boot Disk.

ebois

Sometimes spuriously listed as having failed to load in Bootlog.txt. See Microsoft KnowledgeBase article 127970 for details of the various spurious error messages which can appear in Bootlog.txt.

ECC

Error Correcting Code. By adding several redundant bits to each byte, single bit errors (one bit changing from 0 to 1 or vice-versa) can be corrected. The mathematics behind this - Galois Theory - is very complicated but interesting. The technique can be used in any data storage or transmission system where a low error rate is likely to occur. Whereas a simple parity system will detect an error, it will not correct it.

EDIT > UNDO

A facility provided in many programs which cancels the effect of the immediately previous operation. However, in most cases only the immediately previous operation can be undone. A few small number of programs provide multiple undo, allowing a series of operations to be undone, in reverse order. Since typing a single character is in itself an operation, multiple undo is extremely useful.

EditPad

See Notepad.

EDO

A type of ram. Not quite as fast as SDRAM.

edu

The Internet top-level domain for educational institutions (universities, schools, etc).

EFS

Encrypted File System. A security feature in Windows XP (Professional Edition only).

EIDE

A more modern version of IDE.

Ellipsis

... (see that entry).

Email Client

An email program or a web browser which includes email facilities.

EMF

File extension. Enhanced metafile. A graphics file format.

Emoticon

A symbol constructed from two or more characters, read sideways, used to convey an emotion or to indicate the sense in which a comment was made. The two best known examples are :) and :(. There are numerous others, in my opinion best ignored.

Empty

In HTML an empty tag is one which does not have a corresponding ending tag. It is called "empty" since it doesn't "contain" any text (between a starting tag and an ending tag).

Empty tags include <HR> (horizontal rule) and <IMG> (image).

Emulator

A program which allows one type of computer to mimic another and thereby to run programs written for that other computer. For example, it is possible to obtain an emulator which enables Microsoft Windows to run programs written for the Commodore 64. Emulators inevitably tend to be somewhat less than perfect and can be slow unless the emulating computer is much faster than the emulated computer. Sometimes emulators are purely software, sometimes - together with the necessary electronics - they can allow the other computer's peripherals to be connected to the emulating computer, allowing the actual original programs and data to be loaded.

Encapsulation

A term used in object oriented programming. It appears to refer to the use of objects without needing to know how they operate internally. Since this concept also applies to subroutines and functions, it is hardly revolutionary.

Encarta

Microsoft's CD-ROM encyclopedia.

Encoder

A program which encodes data, or converts it to another format. In the context of MP3, an encoder is a program which converts from another sound file format into MP3 format. Similarly, there are Ogg encoders which convert a WAV file into an Ogg file.

Enter Key

See Return Key.

Entry-level

The least expensive model in a manufacturer's range of models.

Enumerate

Enumeration appears to be the process in which the Plug and Play system automatically allocates I/O addresses and IRQ and DMA channels to devices. I suspect that the word may have additional meanings.

ERP

Enterprise Resource Planning.

Opinion: This appears to be a largely meaningless management and marketing pseudo-technical term.

Esc Key

The Escape key at the top-left corner of the keyboard. The Esc key is often used to cancel a dialog box or to "back out" of a menu option.

Escape Sequence

Control information inserted into a stream of data, introduced by the Escape character (ASCII code 27). In the past, escape sequences were used to control the pitch and other print settings on printers. They were also used to control the format of text displayed on VDU's. I imagine that escape sequences may still be used with printers but since the introduction of Windows these matters have been completely hidden to the user.

ESCD

Extended System Configuration Data. An area in the BIOS which holds Plug And Play information, amongst other things. If the ESCD becomes corrupted then the computer will normally either fail to boot or exhibit serious problems. In that case, go into the BIOS and use the appropriate option to clear the ESCD. The next time the computer boots it will automatically rebuild the information.

ESP

See "Microsoft ESP".

ETLA

Extended Three Letter Acronym. "ETLA" is itself an ETLA. :)

EULA

End User Licence Agreement. The fine print which appears during installation and is normally ignored. However, licence agreements are worth scanning, mainly to warn you of software which adds stealth advertising and other unwanted material on your computer.

Event

A term used in many modern programming languages. The program reacts to events such as the mouse being clicked, a keyboard key being pressed, etc.

Event Driven

A style of programming and programming language in which programs react to external events, such as the user clicking on a button with the mouse. Event driven programs have to be able to react to anything the user might do, and in many cases also to anything that other programs might do. All Windows programs are event driven. Event driven is the opposite of procedural.

Excel

A spreadsheet program published by Microsoft. Also called XL.

Exchange

A Microsoft email program. Now defunct and replaced by Outlook, I believe.

Opinion: Exchange was one of worst examples of bloatware known to man.

Excite

A well known search engine.

http://www.excite.com

EXD

File extension. An EXD file is automatically created when an Active X control is used. EXD files are normally created in folders (which are also automatically created as needed) within C:\WINDOWS\TEMP, including C:\WINDOWS\TEMP\VBE. Microsoft KnowledgeBase article 290537 has more information. EXD files can probably contain viruses.

EXE

"ex-eee". File extension. Executable file - i.e. a compiled program file. EXE files can contain viruses.

Executable

A compiled program file (usually an EXE file).

Explorer

Windows Explorer, the program used to list the contents of folders, and to move, copy, delete and rename files and folders, etc.
Internet Explorer, the web browser program.
MSN Explorer. I think this is a web browser program.
An internal program which always appears on the Task List in Windows 95 (and presumably its successors). I suspect that this may be program which runs the Windows desktop.

Expose

Another object oriented programming/Microsoft marketing-speak jargon word, increasingly being used. It is very tempting to dismiss this word as not having any meaning. However, I think it actually refers to the concept of pieces of software (programs, subroutines, procedures, objects, etc) having external interfaces, both inputs and outputs.

Extend

In the sense of extending a class, see "Inheritance".

Express

Outlook Express, the email program very closely tied in with Internet Explorer. Not to be confused with Outlook, the reminders program supplied as part of Microsoft Office.
Visual Web Developer 2005 Express Edition, Visual Basic 2005 Express Edition, Visual C# 2005 Express Edition, Visual C++ 2005 Express Edition, Visual J# 2005 Express Edition and SQL Server Express Edition - cut-down free trial editions of these products, released by Microsoft in the summer of 2005, presumably in reaction to a slow take-up of the full versions.

External Cache

See "Cache".

Introduction

Punctuation 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

PC and Internet Hints

Overall Site Home Page

About this personal web site JohnCletheroe

EMail me

Most recently modified 1-Nov-08