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

AZW file extension

Amazon Kindle eBook File

eBook Files

CFM file extension

ColdFusion Markup File

Web Files

CS file extension

Visual C# Source Code File

Developer Files

DAT file extension

Data File

Data Files

DEM file extension

Video Game Demo File

Game Files

LNK file extension

Windows File Shortcut

System Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

ODT file extension

OpenDocument Text Document

Text Files

PIF file extension

Program Information File

Executable Files

PSD file extension

Adobe Photoshop Document

Raster Image Files

RTF file extension

Rich Text Format File

Text Files

TAR file extension

Consolidated Unix File Archive

Data Files

TGA file extension

Targa Graphic

Raster Image Files

TORRENT file extension

BitTorrent File

Misc Files

WMV file extension

Windows Media Video File

Video Files