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

AIF file extension

Audio Interchange File Format

Audio Files

APK file extension

Android Package File

Executable Files

COM file extension

DOS Command File

Executable Files

CS file extension

Visual C# Source Code File

Developer Files

DB file extension

Database File

Database Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

LNK file extension

Windows File Shortcut

System Files

M3U file extension

Media Playlist File

Audio Files

MID file extension

MIDI File

Audio Files

MOV file extension

Apple QuickTime Movie

Video Files

MPG file extension

MPEG Video File

Video Files

SITX file extension

StuffIt X Archive

Compressed Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

TIF file extension

Tagged Image File

Raster Image Files

3G2 file extension

3GPP2 Multimedia File

Video Files