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

SDF file extension

Standard Data File

Data Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

DOC# file extension

Microsoft Word Document

Text Files

7Z file extension

7-Zip Compressed File

Compressed Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

CPL file extension

Windows Control Panel Item

System Files

3G2 file extension

3GPP2 Multimedia File

Video Files

CFG file extension

Configuration File

Settings Files

MAX file extension

3ds Max Scene File

3D Image Files

ICNS file extension

Mac OS X Icon Resource File

System Files

VB file extension

VBScript File

Executable Files

ODT file extension

OpenDocument Text Document

Text Files

TIF file extension

Tagged Image File

Raster Image Files

JAR file extension

Java Archive File

Executable Files

GADGET file extension

Windows Gadget

Executable Files