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

AVI file extension

Audio Video Interleave File

Video Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

DB file extension

Database File

Database Files

DMP file extension

Windows Memory Dump

System Files

GADGET file extension

Windows Gadget

Executable Files

H file extension

C/C++/Objective-C Header File

Developer Files

M4A file extension

MPEG-4 Audio File

Audio Files

MPA file extension

MPEG-2 Audio File

Audio Files

PRF file extension

Outlook Profile File

Settings Files

RA file extension

Real Audio File

Audio Files

RSS file extension

Rich Site Summary

Web Files

SWF file extension

Shockwave Flash Movie

Video Files

TAR file extension

Consolidated Unix File Archive

Data Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

TGA file extension

Targa Graphic

Raster Image Files