File Extensions
File extensions are usually added automatically to the file name when you save a document. All Windows Operating Systems recognize common file extensions and will open the file in the correct application automatically, provided you have the program installed on your computer. For example, double-clicking on a file named "this.doc" will open the document using Microsoft Word. If you have problems opening a file, the most common problem is you do not have the program installed on your computer. Changing a files default extension can also cause the file not to open correctly.
The following is a list of common file extensions used and what program for file type they are related to.
Text Files
DOC Word or WordPerfect
PDF Portable document file
RTF Rich Text Format
TXT TEXT file
WPD WordPerfect Document
Audio, Video, and
Graphics Files
AU audio file
AVI movie file
BMP Windows bitmap often created by the Windows Paint program. Typically, BMP
files are uncompressed and very large.
GIF graphics file (Graphics Interchange Format) The GIF format suitable for
storing graphics with relatively few colors such as simple diagrams, shapes,
logos and cartoons.
JPG or JPEG graphics file (Joint Photographic Experts Group) is a compression
method these files are typically found on web pages and used for emailing pictures.
MOV Apple Quick Time movie file
MP3 - MPEG Audio Layer 3.
MPG MPEG - Animation file format.
PNG (Portable Network Graphics) file format was created as the free, open-source
successor to the GIF format.
RA RAM Real Audio file
TIF or TIFF graphics file
WAVor WAVE audio file
Presentation Formats
PPT PowerPoint presentation files
Application Formats
(Note, these are executable files, when you double click on them they do something.)
BAT Batch file
EXE Executable file
COM command executable file
JS JAVA Script
PL PERL Script
Compression Formats
ZIP or PKZIP compressed file. The most common use of zip files is to bundle
together several files into one file for emailing and distribution on disks.
It will also make the file or files smaller than their original size.
Web Pages
HTM or HTML Hyper Text Markup Language.