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

ASX file extension

Microsoft ASF Redirector File

Video Files

C file extension

C/C++ Source Code File

Developer Files

CRX file extension

Chrome Extension

Plugin Files

GAM file extension

Saved Game File

Game Files

H file extension

C/C++/Objective-C Header File

Developer Files

JSP file extension

Java Server Page

Web Files

MP4 file extension

MPEG-4 Video File

Video Files

PAGES file extension

Pages Document

Text Files

PHP file extension

PHP Source Code File

Web Files

PIF file extension

Program Information File

Executable Files

RA file extension

Real Audio File

Audio Files

ROM file extension

N64 Game ROM File

Game Files

TTF file extension

TrueType Font

Font Files

YUV file extension

YUV Encoded Image File

Raster Image Files

3GP file extension

3GPP Multimedia File

Video Files