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

M4A file extension

MPEG-4 Audio File

Audio Files

M3U file extension

Media Playlist File

Audio Files

7Z file extension

7-Zip Compressed File

Compressed Files

CUE file extension

Cue Sheet File

Disk Image Files

FNT file extension

Windows Font File

Font Files

LNK file extension

Windows File Shortcut

System Files

WMA file extension

Windows Media Audio File

Audio Files

NES file extension

Nintendo (NES) ROM File

Game Files

DOC file extension

Microsoft Word Document

Text Files

RSS file extension

Rich Site Summary

Web Files

SWF file extension

Shockwave Flash Movie

Video Files

CSV file extension

Comma Separated Values File

Data Files

TEX file extension

LaTeX Source Document

Text Files

3DS file extension

3D Studio Scene

3D Image Files

SAV file extension

Saved Game

Game Files