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

CBR file extension

Comic Book RAR Archive

Compressed Files

DEB file extension

Debian Software Package

Compressed Files

GZ file extension

Gnu Zipped Archive

Compressed Files

IFF file extension

Interchange File Format

Audio Files

MOV file extension

Apple QuickTime Movie

Video Files

MP3 file extension

MP3 Audio File

Audio Files

PAGES file extension

Pages Document

Text Files

PART file extension

Partially Downloaded File

Misc Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

PS file extension

PostScript File

Vector Image Files

RA file extension

Real Audio File

Audio Files

RSS file extension

Rich Site Summary

Web Files

TIF file extension

Tagged Image File

Raster Image Files

3GP file extension

3GPP Multimedia File

Video Files