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

DBF file extension

Database File

Database Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

GBR file extension

Gerber File

Data Files

KMZ file extension

Google Earth Placemark File

GIS Files

M file extension

Objective-C Implementation File

Developer Files

M3U file extension

Media Playlist File

Audio Files

MOBI file extension

Mobipocket eBook

eBook Files

NES file extension

Nintendo (NES) ROM File

Game Files

OBJ file extension

Wavefront 3D Object File

3D Image Files

SRT file extension

SubRip Subtitle File

Video Files

TGA file extension

Targa Graphic

Raster Image Files

TORRENT file extension

BitTorrent File

Misc Files

VOB file extension

DVD Video Object File

Video Files

WMV file extension

Windows Media Video File

Video Files

XLR file extension

Works Spreadsheet

Spreadsheet Files