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

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

PL file extension

Perl Script

Developer Files

CFG file extension

Configuration File

Settings Files

CRX file extension

Chrome Extension

Plugin Files

ICNS file extension

Mac OS X Icon Resource File

System Files

WPD file extension

WordPerfect Document

Text Files

PART file extension

Partially Downloaded File

Misc Files

TXT file extension

Plain Text File

Text Files

PCT file extension

Picture File

Layout Files

TIF file extension

Tagged Image File

Raster Image Files

ASX file extension

Microsoft ASF Redirector File

Video Files

7Z file extension

7-Zip Compressed File

Compressed Files

CPL file extension

Windows Control Panel Item

System Files

APK file extension

Android Package File

Executable Files

CPP file extension

C++ Source Code File

Developer Files