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

APP file extension

Mac OS X Application

Executable Files

FNT file extension

Windows Font File

Font Files

GPX file extension

GPS Exchange File

GIS Files

JAR file extension

Java Archive File

Executable Files

M file extension

Objective-C Implementation File

Developer Files

NES file extension

Nintendo (NES) ROM File

Game Files

PAGES file extension

Pages Document

Text Files

PDF file extension

Portable Document Format File

Layout Files

PHP file extension

PHP Source Code File

Web Files

RA file extension

Real Audio File

Audio Files

SH file extension

Bash Shell Script

Developer Files

TARGZ file extension

Compressed Tarball File

Compressed Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

TGA file extension

Targa Graphic

Raster Image Files

VCXPROJ file extension

Visual C++ Project

Developer Files