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

PAGES file extension

Pages Document

Text Files

3DM file extension

Rhino 3D Model

3D Image Files

M3U file extension

Media Playlist File

Audio Files

XML file extension

XML File

Data Files

CGI file extension

Common Gateway Interface Script

Executable Files

7Z file extension

7-Zip Compressed File

Compressed Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

BMP file extension

Bitmap Image File

Raster Image Files

VCF file extension

vCard File

Data Files

ZIPX file extension

Extended Zip File

Compressed Files

SAV file extension

Saved Game

Game Files

LUA file extension

Lua Source File

Developer Files

KML file extension

Keyhole Markup Language File

GIS Files

COM file extension

DOS Command File

Executable Files

UUE file extension

Uuencoded File

Encoded Files