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

AI file extension

Adobe Illustrator File

Vector Image Files

DEB file extension

Debian Software Package

Compressed Files

DEM file extension

Video Game Demo File

Game Files

DRV file extension

Device Driver

System Files

GIF file extension

Graphical Interchange Format File

Raster Image Files

ICS file extension

iCalendar File

Misc Files

JS file extension

JavaScript File

Web Files

LUA file extension

Lua Source File

Developer Files

M file extension

Objective-C Implementation File

Developer Files

MOBI file extension

Mobipocket eBook

eBook Files

MPA file extension

MPEG-2 Audio File

Audio Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

SQL file extension

Structured Query Language Data File

Database Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

3G2 file extension

3GPP2 Multimedia File

Video Files