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

CLASS file extension

Java Class File

Developer Files

CRX file extension

Chrome Extension

Plugin Files

DOC file extension

Microsoft Word Document

Text Files

GAM file extension

Saved Game File

Game Files

H file extension

C/C++/Objective-C Header File

Developer Files

JPG file extension

JPEG Image

Raster Image Files

KMZ file extension

Google Earth Placemark File

GIS Files

LNK file extension

Windows File Shortcut

System Files

MPA file extension

MPEG-2 Audio File

Audio Files

PCT file extension

Picture File

Layout Files

PHP file extension

PHP Source Code File

Web Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

VCXPROJ file extension

Visual C++ Project

Developer Files

ZIPX file extension

Extended Zip File

Compressed Files