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

WPD file extension

WordPerfect Document

Text Files

NES file extension

Nintendo (NES) ROM File

Game Files

KML file extension

Keyhole Markup Language File

GIS Files

7Z file extension

7-Zip Compressed File

Compressed Files

GZ file extension

Gnu Zipped Archive

Compressed Files

JAVA file extension

Java Source Code File

Developer Files

SAV file extension

Saved Game

Game Files

BMP file extension

Bitmap Image File

Raster Image Files

RPM file extension

Red Hat Package Manager File

Compressed Files

UUE file extension

Uuencoded File

Encoded Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

CFM file extension

ColdFusion Markup File

Web Files

CBR file extension

Comic Book RAR Archive

Compressed Files

KEY file extension

Keynote Presentation

Data Files

TORRENT file extension

BitTorrent File

Misc Files