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

SH file extension

Bash Shell Script

Developer Files

FLA file extension

Adobe Flash Animation

Developer Files

KML file extension

Keyhole Markup Language File

GIS Files

CBR file extension

Comic Book RAR Archive

Compressed Files

CSR file extension

Certificate Signing Request File

Web Files

7Z file extension

7-Zip Compressed File

Compressed Files

GPX file extension

GPS Exchange File

GIS Files

TORRENT file extension

BitTorrent File

Misc Files

SDF file extension

Standard Data File

Data Files

GIF file extension

Graphical Interchange Format File

Raster Image Files

DEM file extension

Video Game Demo File

Game Files

XML file extension

XML File

Data Files

M4A file extension

MPEG-4 Audio File

Audio Files

PKG file extension

Mac OS X Installer Package

Compressed Files

XLR file extension

Works Spreadsheet

Spreadsheet Files