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

UUE file extension

Uuencoded File

Encoded Files

ASP file extension

Active Server Page

Web Files

DRV file extension

Device Driver

System Files

INDD file extension

Adobe InDesign Document

Layout Files

ZIPX file extension

Extended Zip File

Compressed Files

DEM file extension

Video Game Demo File

Game Files

MSI file extension

Windows Installer Package

Misc Files

LNK file extension

Windows File Shortcut

System Files

VB file extension

VBScript File

Executable Files

7Z file extension

7-Zip Compressed File

Compressed Files

BIN file extension

Binary Disc Image

Disk Image Files

CGI file extension

Common Gateway Interface Script

Executable Files

TIFF file extension

Tagged Image File Format

Raster Image Files

AIF file extension

Audio Interchange File Format

Audio Files

XCODEPROJ file extension

Xcode Project

Developer Files