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

AIF file extension

Audio Interchange File Format

Audio Files

APK file extension

Android Package File

Executable Files

ASPX file extension

Active Server Page Extended File

Web Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

GPX file extension

GPS Exchange File

GIS Files

INDD file extension

Adobe InDesign Document

Layout Files

JAVA file extension

Java Source Code File

Developer Files

KEYCHAIN file extension

Mac OS X Keychain File

Data Files

PCT file extension

Picture File

Layout Files

SWF file extension

Shockwave Flash Movie

Video Files

TARGZ file extension

Compressed Tarball File

Compressed Files

TEX file extension

LaTeX Source Document

Text Files

VB file extension

VBScript File

Executable Files

VOB file extension

DVD Video Object File

Video Files

WSF file extension

Windows Script File

Executable Files