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

KML file extension

Keyhole Markup Language File

GIS Files

GPX file extension

GPS Exchange File

GIS Files

FON file extension

Generic Font File

Font Files

DRV file extension

Device Driver

System Files

SYS file extension

Windows System File

System Files

M file extension

Objective-C Implementation File

Developer Files

IBOOKS file extension

Multi-Touch iBook

Data Files

KMZ file extension

Google Earth Placemark File

GIS Files

7Z file extension

7-Zip Compressed File

Compressed Files

UUE file extension

Uuencoded File

Encoded Files

EXE file extension

Windows Executable File

Executable Files

WSF file extension

Windows Script File

Executable Files

BMP file extension

Bitmap Image File

Raster Image Files

DAT file extension

Data File

Data Files

WPS file extension

Microsoft Works Word Processor Document

Text Files