File extensions – definition and basic information


File extensions are the integral parts of the files that are on each computer. Often, when working on a computer, we encounter a wide range of files, such as docx, ppt, part, mp3 or rmvb. We realize that they are there – but we often do not know what they are for on our computer.

File extension, also known as the filename extension is a suffix added to the name of a computer file, usually consisting of a number of characters placed after the last dot in the filename, which gives us information about its coding. In other words a file extension is a file format. It allows the operating system (e.g. Windows) to recognize what program it should try to open the file.

In the table below you will find a random selection of popular file extensions.


File extension The full name of the file Category

CFM file extension

ColdFusion Markup File

Web Files

CRX file extension

Chrome Extension

Plugin Files

CUE file extension

Cue Sheet File

Disk Image Files

DLL file extension

Dynamic Link Library

System Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

DRV file extension

Device Driver

System Files

DXF file extension

Drawing Exchange Format File

CAD Files

FLA file extension

Adobe Flash Animation

Developer Files

GZ file extension

Gnu Zipped Archive

Compressed Files

M4V file extension

iTunes Video File

Video Files

PIF file extension

Program Information File

Executable Files

ROM file extension

N64 Game ROM File

Game Files

RPM file extension

Red Hat Package Manager File

Compressed Files

VB file extension

VBScript File

Executable Files

WMA file extension

Windows Media Audio File

Audio Files