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

ASF file extension

Advanced Systems Format File

Video Files

CFG file extension

Configuration File

Settings Files

CPL file extension

Windows Control Panel Item

System Files

DLL file extension

Dynamic Link Library

System Files

FLA file extension

Adobe Flash Animation

Developer Files

FNT file extension

Windows Font File

Font Files

GPX file extension

GPS Exchange File

GIS Files

KEY file extension

Keynote Presentation

Data Files

MAX file extension

3ds Max Scene File

3D Image Files

PDB file extension

Program Database

Database Files

RSS file extension

Rich Site Summary

Web Files

TIF file extension

Tagged Image File

Raster Image Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

3G2 file extension

3GPP2 Multimedia File

Video Files