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

ASX file extension

Microsoft ASF Redirector File

Video Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

DLL file extension

Dynamic Link Library

System Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

EXE file extension

Windows Executable File

Executable Files

IBOOKS file extension

Multi-Touch iBook

Data Files

M4V file extension

iTunes Video File

Video Files

MPA file extension

MPEG-2 Audio File

Audio Files

NES file extension

Nintendo (NES) ROM File

Game Files

PART file extension

Partially Downloaded File

Misc Files

PPS file extension

PowerPoint Slide Show

Data Files

RSS file extension

Rich Site Summary

Web Files

VB file extension

VBScript File

Executable Files

VCD file extension

Virtual CD

Disk Image Files

3DM file extension

Rhino 3D Model

3D Image Files