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

FLA file extension

Adobe Flash Animation

Developer Files

SH file extension

Bash Shell Script

Developer Files

WAV file extension

WAVE Audio File

Audio Files

7Z file extension

7-Zip Compressed File

Compressed Files

TMP file extension

Temporary File

Backup Files

OTF file extension

OpenType Font

Font Files

DDS file extension

DirectDraw Surface

Raster Image Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

KML file extension

Keyhole Markup Language File

GIS Files

DEM file extension

Video Game Demo File

Game Files

RSS file extension

Rich Site Summary

Web Files

KMZ file extension

Google Earth Placemark File

GIS Files

COM file extension

DOS Command File

Executable Files

CPP file extension

C++ Source Code File

Developer Files

3GP file extension

3GPP Multimedia File

Video Files