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

ASP file extension

Active Server Page

Web Files

C file extension

C/C++ Source Code File

Developer Files

CRX file extension

Chrome Extension

Plugin Files

DNG file extension

Digital Negative Image File

Camera Raw Files

HQX file extension

BinHex 4.0 Encoded File

Encoded Files

ICO file extension

Icon File

System Files

MP4 file extension

MPEG-4 Video File

Video Files

MPA file extension

MPEG-2 Audio File

Audio Files

ROM file extension

N64 Game ROM File

Game Files

SAV file extension

Saved Game

Game Files

SDF file extension

Standard Data File

Data Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

VCF file extension

vCard File

Data Files

WMA file extension

Windows Media Audio File

Audio Files

ZIP file extension

Zipped File

Compressed Files