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

ASF file extension

Advanced Systems Format File

Video Files

AZW file extension

Amazon Kindle eBook File

eBook Files

DEM file extension

Video Game Demo File

Game Files

DRV file extension

Device Driver

System Files

GPX file extension

GPS Exchange File

GIS Files

M3U file extension

Media Playlist File

Audio Files

MPG file extension

MPEG Video File

Video Files

PPT file extension

PowerPoint Presentation

Data Files

SITX file extension

StuffIt X Archive

Compressed Files

SLN file extension

Visual Studio Solution File

Developer Files

SQL file extension

Structured Query Language Data File

Database Files

TARGZ file extension

Compressed Tarball File

Compressed Files

YUV file extension

YUV Encoded Image File

Raster Image Files

3DM file extension

Rhino 3D Model

3D Image Files

3G2 file extension

3GPP2 Multimedia File

Video Files