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

AIF file extension

Audio Interchange File Format

Audio Files

CUE file extension

Cue Sheet File

Disk Image Files

DB file extension

Database File

Database Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

DLL file extension

Dynamic Link Library

System Files

DNG file extension

Digital Negative Image File

Camera Raw Files

GZ file extension

Gnu Zipped Archive

Compressed Files

ICO file extension

Icon File

System Files

IFF file extension

Interchange File Format

Audio Files

INDD file extension

Adobe InDesign Document

Layout Files

MAX file extension

3ds Max Scene File

3D Image Files

PS file extension

PostScript File

Vector Image Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

UUE file extension

Uuencoded File

Encoded Files