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

CPL file extension

Windows Control Panel Item

System Files

CSV file extension

Comma Separated Values File

Data Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

GPX file extension

GPS Exchange File

GIS Files

ICO file extension

Icon File

System Files

OTF file extension

OpenType Font

Font Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

RA file extension

Real Audio File

Audio Files

RPM file extension

Red Hat Package Manager File

Compressed Files

SITX file extension

StuffIt X Archive

Compressed Files

TGA file extension

Targa Graphic

Raster Image Files

WMA file extension

Windows Media Audio File

Audio Files

WMV file extension

Windows Media Video File

Video Files

WSF file extension

Windows Script File

Executable Files

XLR file extension

Works Spreadsheet

Spreadsheet Files