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

CFG file extension

Configuration File

Settings Files

CUE file extension

Cue Sheet File

Disk Image Files

DEM file extension

Video Game Demo File

Game Files

ICS file extension

iCalendar File

Misc Files

M3U file extension

Media Playlist File

Audio Files

M4A file extension

MPEG-4 Audio File

Audio Files

MID file extension

MIDI File

Audio Files

NES file extension

Nintendo (NES) ROM File

Game Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

RPM file extension

Red Hat Package Manager File

Compressed Files

RSS file extension

Rich Site Summary

Web Files

SLN file extension

Visual Studio Solution File

Developer Files

TORRENT file extension

BitTorrent File

Misc Files

VCD file extension

Virtual CD

Disk Image Files