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

MOV file extension

Apple QuickTime Movie

Video Files

MSG file extension

Outlook Mail Message

Text Files

ICNS file extension

Mac OS X Icon Resource File

System Files

7Z file extension

7-Zip Compressed File

Compressed Files

DBF file extension

Database File

Database Files

GAM file extension

Saved Game File

Game Files

ASX file extension

Microsoft ASF Redirector File

Video Files

TIF file extension

Tagged Image File

Raster Image Files

PNG file extension

Portable Network Graphic

Raster Image Files

SH file extension

Bash Shell Script

Developer Files

CPL file extension

Windows Control Panel Item

System Files

LNK file extension

Windows File Shortcut

System Files

MPG file extension

MPEG Video File

Video Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

3G2 file extension

3GPP2 Multimedia File

Video Files