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

DLL file extension

Dynamic Link Library

System Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

GADGET file extension

Windows Gadget

Executable Files

GPX file extension

GPS Exchange File

GIS Files

ICS file extension

iCalendar File

Misc Files

IFF file extension

Interchange File Format

Audio Files

M file extension

Objective-C Implementation File

Developer Files

M3U file extension

Media Playlist File

Audio Files

PAGES file extension

Pages Document

Text Files

RA file extension

Real Audio File

Audio Files

TGA file extension

Targa Graphic

Raster Image Files

THM file extension

Thumbnail Image File

Raster Image Files

VCXPROJ file extension

Visual C++ Project

Developer Files

WMV file extension

Windows Media Video File

Video Files

YUV file extension

YUV Encoded Image File

Raster Image Files