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

CPP file extension

C++ Source Code File

Developer Files

DAT file extension

Data File

Data Files

DB file extension

Database File

Database Files

DTD file extension

Document Type Definition File

Developer Files

GED file extension

GEDCOM Genealogy Data File

Data Files

GZ file extension

Gnu Zipped Archive

Compressed Files

INI file extension

Windows Initialization File

Settings Files

KMZ file extension

Google Earth Placemark File

GIS Files

MPA file extension

MPEG-2 Audio File

Audio Files

PKG file extension

Mac OS X Installer Package

Compressed Files

PL file extension

Perl Script

Developer Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

SAV file extension

Saved Game

Game Files

TIFF file extension

Tagged Image File Format

Raster Image Files

VB file extension

VBScript File

Executable Files