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

ASF file extension

Advanced Systems Format File

Video Files

CPL file extension

Windows Control Panel Item

System Files

CS file extension

Visual C# Source Code File

Developer Files

DB file extension

Database File

Database Files

DBF file extension

Database File

Database Files

DNG file extension

Digital Negative Image File

Camera Raw Files

FON file extension

Generic Font File

Font Files

GADGET file extension

Windows Gadget

Executable Files

GIF file extension

Graphical Interchange Format File

Raster Image Files

LOG file extension

Log File

Text Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

RSS file extension

Rich Site Summary

Web Files

SLN file extension

Visual Studio Solution File

Developer Files

TEX file extension

LaTeX Source Document

Text Files

3G2 file extension

3GPP2 Multimedia File

Video Files