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

AZW file extension

Amazon Kindle eBook File

eBook Files

CRX file extension

Chrome Extension

Plugin Files

DRV file extension

Device Driver

System Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

ICNS file extension

Mac OS X Icon Resource File

System Files

ICS file extension

iCalendar File

Misc Files

KML file extension

Keyhole Markup Language File

GIS Files

M4A file extension

MPEG-4 Audio File

Audio Files

PL file extension

Perl Script

Developer Files

ROM file extension

N64 Game ROM File

Game Files

SLN file extension

Visual Studio Solution File

Developer Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

TORRENT file extension

BitTorrent File

Misc Files

WPD file extension

WordPerfect Document

Text Files