• Tridev Computers

What are file extensions??

Updated: Aug 28

What is the file extensions??

What are file extensions

A file extension, or file name extension, is the letters immediately shown after the last period in a file name. For example, the file extension.txt has an extension of .txt. This extension allows the operating system to know what type of file it is and what program to run when you double-click on it. There are no particular rules regarding how an extension should be formatted other than it must begin with a period and have at least one character after it. For the most part, file extensions consist of three characters, which are typically letters or digits, that textually represent the type of file it is. Some examples of file extensions include .txt, .mp3, .jpg, and .gz, which represent text files, mp3 files, jpeg image files, and files compressed with the zip program. As you can see, the actual extension name gives clues as to the type of file it is.


As already said, an operating system knows what programs to use in order to view, print, or edit a particular file by looking at its file extension. It is able to do this because each operating system has in its configuration a default mapping between a particular file extension and a particular program. Using this information, when a user clicks on a file, the operating reads the file extension and then launches the mapped application. Typically, if the extension is unknown to the operating system or no application mapping exists, it will prompt the user to specify the program that it would like to open the file with.


How to change the program associated with a file extension

As already mentioned, file extensions are mapped to a particular program so that when you attempt to use the file, the operating system knows which application to launch. There may come a time that you wish to change a default association so that you can use a different program to automatically open the file. For example, when you open a image file on Windows it defaults to using the pre-installed Windows Photo Viewer. In the future if you find a new program that you would like to use instead, you can change the associations for image files so that they instead are opened by the new program.

For more information about how to change the default program a file extension opens with, please select one of the tutorials below based upon your particular operating system:




Common File Extensions

Below are a list of common file extensions that you may find on your computer or over the Internet.

Audio Extensions


Extension Description


.aif A Audio Interchange File is an audio file format that is

most commonly used on Apple Macintosh

computer systems.


.m3u M3U files are used to store multimedia play lists.


.mp3 An MP3 file is the most common file format used to store

digital audio for use on computers and

digital media devices.


.ra Audio files created by RealAudio.


.wav A WAV, or Waveform Audio File Format, is a audio file

format used to store audio on PCs.


.wma Windows Media Audio, or WMA, files is a audio file format

developed by Microsoft.

Video Extensions


Extension Description

.avi A Audio Video Interleave, or AVI, file is a video and

audio file created by Microsoft.


.flv Flash video files.


.mov Apple QuickTime movie.


.mp4 A video file.


.mpg A MPEG video file.


wmv A Windows Media Video, or WMV, file is a video file

type created by Microsoft.

Image Extensions


Extension Description

.bmp A Bitmap, or BMP, file is an image file used to store

bitmap digital images. These files are typically found in

Windows.


.cur The CUR file format is used to store non-animated cursors

in Windows.


.ico The ICO file format is used to store computer icons in

Microsoft Windows.


.gif A Graphics Interchange Format, or GIF, is an image file

format created by Compuserve. This is a common format

to find on a computer and the Internet.


.jpg A JPEG image file is a common file found on computers

and the Internet.


.jpeg Another extension that corresponds to a JPEG image file.


.png A Portable Network Graphic, or PNG, is an image file that

was created to replace GIF files. This is a common format

to find on a computer and the Internet.


.psd A Photoshop Document, or PSD, file is used to store

images created by Adobe Photoshop.


.raw The raw image format is commonly used by digital

cameras to save a picture in a format that has not

currently been processed.


.tif The Tagged Image File Format, or TIF, is an image file

that is commonly used by graphic artists and

photographers.

Workplace Applications and Text Files Extensions


Extension Description

.csv A Comma Separated Value, or CSV, file is a text file that

contains lines of data that are separated by commas.


.doc A Word Document, or DOC, file is the extension that Word

would save its documents.


.docx Starting in Word 2007, the .docx file format became the

standard file that Microsoft Word would save files as.


.log A text file typically containing a textual log of what an

application or computer process has done or transmitted.


.pdf A Portable Document Format, or PDF, file is a file format

that was created by Adobe Systems. This file format is

used to create documents that contain a specific fixed

layout regardless of the operating system or application

that opens them.


.pps A Microsoft PowerPoint slide show file.


.ppt A PowerPoint Document, or PPT, file is the extension that

PowerPoint would save its documents.


.pptx Starting in PowerPoint 2007, the .pptx file format became

the standard file that Microsoft PowerPoint would save

files as.


.rtf A Rich Text Format, or RTF, file was created by Microsoft

to allow the formatting of text, such as bold or underline,

in a text document.


.txt A text file is a file that contains textual data without any

formatting.


.wpd The standard file format for saving WordPerfect

documents.


.wps A Microsoft Works document.


.xlr A Microsoft Works spreadsheet file.


.xls A Excel Document, or XLS, was the standard file format

that Microsoft Excel would saved files as. This was

changed to .xlsx starting with Excel 2007.


.xlsx Starting in Excel 2007, the .docx file format became the

standard file that Microsoft Excel would save files as.

Compressed Files or Archive Extensions

Extension Description

.7z An archive format that was originally created by the

7-Zip archiver.


.bz2 A file that was compressed using bzip2. This file format is

commonly used on Linux and Unix systems.


.cab A Cabinet, or CAB, file is a compressed archive format

used by Microsoft.


.deb A Debian Software Package, or DEB, file is a file used to

install applications in Debian.


.gz A file that was compressed using gzip. This file format is

commonly used on Linux and Unix systems.


.pkg A Package, or PKG, file is a file used to install applications

in Apple OS.


.rar A Roshal Archive, or RAR, file is an archive format used

by WinRar.


.rpm A RPM Package Manager, or RPM, is a file that used to

install applications in Linux operating systems.


.sit A Stuffit, or SIT, file is a compressed archive that was

developed by Stuffit.


.sitx A Stuffit X-compressed, or SITX, file is a compressed

archive from Stuffit.


.tar An archive file created by the Tar utility. This type of file

format is commonly found on the Linux & Unix operating

systems.


.tar.gz A Tar file that was compressed using the Gzip utility.


.zip A ZIP file is a compress archive file. This is the most

common and popular compressed archive that you will

find on a computer and in the Internet. Windows and

Macintosh have built-in support for Zip files.


.Z A file that has been compressed with the Linux or Unix

compress command.






Web & Internet Extensions


Extension Description

.css A Cascading Style Sheets, or CSS, file contains style

sheet language that dictates how the HTML in a HTML file

should be displayed.


.htm A Hypertext Markup Language, or HTML, files contain

HTML markup language, which is used to display

formatted content on web pages.


.html A Hypertext Markup Language, or HTML, files contain

HTML markup language, which is used to display

formatted content on web pages.


.js A Javascript, or JS, file contains scripts that should be

executed by your web browser.


.part When you download a file, the downloaded information

will be stored in a part file until it is completed. Once it is

completed, the file will then be renamed into the files'

name.

Disk Image Extensions

Extension Description

.dmg An Apple Disk Image, or DMG, file is a file that contains a

archive of a hard disk or CD/DVD.


.iso An ISO image is an archive of an optical drive, such as a

CD or DVD drive.

Executable Extensions

Extension Description

.app An Application, or APP, is a Mac OS application. These

applications are actually folders with the extension of

.App.


.bat A batch file is a text file containing a series of commands

that will be executed when the batch file is launched.


.cgi A Common Gateway Interface, or CGI, file is an executable

file that is allowed to run on a web server.


.com This is an executable file for Dos & Windows operating

systems.


.exe This is an executable file for Dos & Windows

operating systems.


.pif A Program Information File, or PIF, file is used to launch a

DOS program in a Windows multi-tasking environment

using certain settings.


.vbs A file containing visual basic script that can be executed

by double-clicking on it.

Windows Extensions


Extension Description

.cpl A Windows Control Panel file. Double-clicking this will

launch the associated control panel.

.dll A Dynamic Link Library, or DLL, is a shared library in

Windows. Executables will use these DLL files in order to

properly run.

.dmp A memory dump file that was generated by Windows

when a program crashed. These memory dump files can

be used to determine why a particular program crashed.

.lnk These types of files are links or shortcuts to an

executable located elsewhere on the Windows operating

system. These .lnk files are just a pointer to the

executable and can be deleted without affecting the

executable itself.

.msi A Windows installer file that can be used to install an

application on your computer.

.reg A Windows Registry file that can be used to make

modifications to the Windows Registry. You should never

double-click on these unless you know what they are

going to do.

.sys A Windows driver files that allows Windows to

communicate with the hardware installed on your

computer.

.tmp A temp file created by a program. These temp files should

be deleted automatically when a program is closed. They

are safe to remove.

Settings Extensions


Extension Description

.cfg A config file that contains configuration information on how a

piece of software should operate.


.conf A config file that contains configuration information on how a

piece of software should operate.


.ini An initialization file that contains settings a program will

configure itself with when it starts.

Font Extensions


Extension Description

.fnt A Windows font file. If you double-click this type of file

you will be able to see the particular font in numerous

sizes.


.fon A Windows font file. If you double-click this type of file

you will be able to see the particular font in numerous

sizes.


.ttf A TrueType font file. If you double-click this type of file

you will be able to see the particular font in numerous

sizes.





50 views

©2020 by Tridev Computer.