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

APK file extension

Android Package File

Executable Files

ASX file extension

Microsoft ASF Redirector File

Video Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

EPUB file extension

Open eBook File

eBook Files

GBR file extension

Gerber File

Data Files

GED file extension

GEDCOM Genealogy Data File

Data Files

JPG file extension

JPEG Image

Raster Image Files

OBJ file extension

Wavefront 3D Object File

3D Image Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

TAR file extension

Consolidated Unix File Archive

Data Files

TOAST file extension

Toast Disc Image

Disk Image Files

TXT file extension

Plain Text File

Text Files

VB file extension

VBScript File

Executable Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

XML file extension

XML File

Data Files