The True Self
At the end of every file there is a dot and an extension, that tells the computer what kind of file it is, just like an id. Can't see your extensions? Depends on your OS, it might be a default for the OS to hide the extensions so it might appear more user friendly. The extension is defined as the very last three or four characters proceed by a period. (for example: .exe) So why is it important to know about these extensions? They tell us what kind of files they are, a key in identifying virus and scumware files via email and internet. With extensions, you can tell that file "mynewpicture.jpg.exe" is really a virus under sheep skin.
To turn on file extensions for WindowsXP, go to 'Start/Settings/Control Panel/Folder Options' and go to the 'View' tab. Uncheck 'Hide extension for known types'.
| Extension Name | Description |
|---|---|
| .123 | Lotus 123 Spreadsheet file |
| .ac3 | A sound format compressed with ac3 codec |
| .asf | Windows Video Streaming File |
| .asp | Microsoft Active Server Pages, Web Forms |
| .avi | Windows Video File, Also DivX or xvid compressed Video |
| .bak | Generic backup files from many applications |
| .bat | Batch File, a scripting file |
| .bmp | Standard image file for windows, highly inefficient. |
| .cpp | C++ source code, a programming language file |
| .dll | Dynamic Link Library, small software that contain drivers to support larger programs |
| .doc | Microsoft Word document |
| .dwg | AutoCAD drawing file |
| .exe | Main Program Executable File |
| .flv | Adobe Flash video file |
| .gif | Internet Image File format, often used for animated images |
| .hlp | Windows Help File |
| .html | Standard Web Page file |
| .inf | Device Driver file |
| .java | Program Files that are built with Java |
| .jpg / .jpeg | Joint Photographic Expert Group, Standard Web image file |
| .jsp | Java Server Pages |
| .log | The log file created by applications, open with a word processor |
| .lwp | Lotus Word Pro documents |
| .midi | Like music notes, these are notes for your soundcard. |
| .mp3 | Music compressed with Layer 3 Mpeg format |
| .mpg / .mpeg | Moving Picture Experts Group, a standard to compress video and audio. |
| .msc | Microsoft Service Control file |
| .ods | OpenOffice Calc spreadsheet file |
| .odt | OpenOffice Writer text file |
| .pif | MS-DOS Porgram. Newer viruses use this rarely known extension to infect you. |
| Adobe Acrobat Document | |
| .png | Portable Network Graphics, a small image file format |
| .ppt | Powerpoint file |
| .psd | Adobe Photoshop file |
| .rtf | Rich Text Format, openable with WordPad |
| .scr | A screen saver file, has the same privileges as the .exe file, a preferred extension to name virus. |
| .swf | Macromedia Flash file |
| .txt | Plain text file |
| .vob | DVD Structure File, contains video and audio for DVD |
| .wav | A primitive audio format |
| .xls | Microsoft Excel File |
