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

ASX file extension

Microsoft ASF Redirector File

Video Files

COM file extension

DOS Command File

Executable Files

CSV file extension

Comma Separated Values File

Data Files

DBF file extension

Database File

Database Files

DEM file extension

Video Game Demo File

Game Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

DRV file extension

Device Driver

System Files

INI file extension

Windows Initialization File

Settings Files

LNK file extension

Windows File Shortcut

System Files

PCT file extension

Picture File

Layout Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

SAV file extension

Saved Game

Game Files

TXT file extension

Plain Text File

Text Files

WMV file extension

Windows Media Video File

Video Files