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

BAT file extension

DOS Batch File

Executable Files

COM file extension

DOS Command File

Executable Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

DEM file extension

Video Game Demo File

Game Files

DRV file extension

Device Driver

System Files

DTD file extension

Document Type Definition File

Developer Files

FON file extension

Generic Font File

Font Files

GAM file extension

Saved Game File

Game Files

GBR file extension

Gerber File

Data Files

MDF file extension

Media Disc Image File

Disk Image Files

MSI file extension

Windows Installer Package

Misc Files

RA file extension

Real Audio File

Audio Files

ROM file extension

N64 Game ROM File

Game Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

XML file extension

XML File

Data Files