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

AVI file extension

Audio Video Interleave File

Video Files

DOC file extension

Microsoft Word Document

Text Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

JPG file extension

JPEG Image

Raster Image Files

KMZ file extension

Google Earth Placemark File

GIS Files

M file extension

Objective-C Implementation File

Developer Files

M4A file extension

MPEG-4 Audio File

Audio Files

MAX file extension

3ds Max Scene File

3D Image Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

TORRENT file extension

BitTorrent File

Misc Files

TTF file extension

TrueType Font

Font Files

VCF file extension

vCard File

Data Files

WPD file extension

WordPerfect Document

Text Files

ZIPX file extension

Extended Zip File

Compressed Files