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

CSS file extension

Cascading Style Sheet

Web Files

GPX file extension

GPS Exchange File

GIS Files

H file extension

C/C++/Objective-C Header File

Developer Files

KML file extension

Keyhole Markup Language File

GIS Files

LUA file extension

Lua Source File

Developer Files

PIF file extension

Program Information File

Executable Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

RPM file extension

Red Hat Package Manager File

Compressed Files

SH file extension

Bash Shell Script

Developer Files

SLN file extension

Visual Studio Solution File

Developer Files

TEX file extension

LaTeX Source Document

Text Files

THM file extension

Thumbnail Image File

Raster Image Files

VB file extension

VBScript File

Executable Files

VCD file extension

Virtual CD

Disk Image Files

VCXPROJ file extension

Visual C++ Project

Developer Files