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

ASF file extension

Advanced Systems Format File

Video Files

AZW file extension

Amazon Kindle eBook File

eBook Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

GADGET file extension

Windows Gadget

Executable Files

KEYCHAIN file extension

Mac OS X Keychain File

Data Files

M3U file extension

Media Playlist File

Audio Files

MOV file extension

Apple QuickTime Movie

Video Files

PART file extension

Partially Downloaded File

Misc Files

PDB file extension

Program Database

Database Files

PPT file extension

PowerPoint Presentation

Data Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

ROM file extension

N64 Game ROM File

Game Files

XCODEPROJ file extension

Xcode Project

Developer Files

ZIP file extension

Zipped File

Compressed Files