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

ASP file extension

Active Server Page

Web Files

C file extension

C/C++ Source Code File

Developer Files

CPL file extension

Windows Control Panel Item

System Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

GBR file extension

Gerber File

Data Files

HTML file extension

Hypertext Markup Language File

Web Files

KMZ file extension

Google Earth Placemark File

GIS Files

MPA file extension

MPEG-2 Audio File

Audio Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

RM file extension

Real Media File

Video Files

SDF file extension

Standard Data File

Data Files

TGA file extension

Targa Graphic

Raster Image Files

WAV file extension

WAVE Audio File

Audio Files

WPD file extension

WordPerfect Document

Text Files

3G2 file extension

3GPP2 Multimedia File

Video Files