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

CBR file extension

Comic Book RAR Archive

Compressed Files

CER file extension

Internet Security Certificate

Web Files

CPL file extension

Windows Control Panel Item

System Files

GADGET file extension

Windows Gadget

Executable Files

GBR file extension

Gerber File

Data Files

H file extension

C/C++/Objective-C Header File

Developer Files

JPG file extension

JPEG Image

Raster Image Files

M3U file extension

Media Playlist File

Audio Files

MOV file extension

Apple QuickTime Movie

Video Files

RM file extension

Real Media File

Video Files

RPM file extension

Red Hat Package Manager File

Compressed Files

RSS file extension

Rich Site Summary

Web Files

SH file extension

Bash Shell Script

Developer Files

VCXPROJ file extension

Visual C++ Project

Developer Files

WMV file extension

Windows Media Video File

Video Files