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

ASP file extension

Active Server Page

Web Files

CRX file extension

Chrome Extension

Plugin Files

CSV file extension

Comma Separated Values File

Data Files

CUE file extension

Cue Sheet File

Disk Image Files

DEM file extension

Video Game Demo File

Game Files

DOC file extension

Microsoft Word Document

Text Files

JSP file extension

Java Server Page

Web Files

KEYCHAIN file extension

Mac OS X Keychain File

Data Files

LUA file extension

Lua Source File

Developer Files

PIF file extension

Program Information File

Executable Files

RSS file extension

Rich Site Summary

Web Files

SH file extension

Bash Shell Script

Developer Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

TGA file extension

Targa Graphic

Raster Image Files

YUV file extension

YUV Encoded Image File

Raster Image Files