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

APK file extension

Android Package File

Executable Files

DDS file extension

DirectDraw Surface

Raster Image Files

DOC# file extension

Microsoft Word Document

Text Files

FON file extension

Generic Font File

Font Files

GAM file extension

Saved Game File

Game Files

GPX file extension

GPS Exchange File

GIS Files

KML file extension

Keyhole Markup Language File

GIS Files

MPA file extension

MPEG-2 Audio File

Audio Files

PAGES file extension

Pages Document

Text Files

PL file extension

Perl Script

Developer Files

RA file extension

Real Audio File

Audio Files

TAR file extension

Consolidated Unix File Archive

Data Files

TMP file extension

Temporary File

Backup Files

VOB file extension

DVD Video Object File

Video Files

WMA file extension

Windows Media Audio File

Audio Files