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

CRX file extension

Chrome Extension

Plugin Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

DXF file extension

Drawing Exchange Format File

CAD Files

GED file extension

GEDCOM Genealogy Data File

Data Files

KMZ file extension

Google Earth Placemark File

GIS Files

PL file extension

Perl Script

Developer Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

SITX file extension

StuffIt X Archive

Compressed Files

TORRENT file extension

BitTorrent File

Misc Files

TTF file extension

TrueType Font

Font Files

VB file extension

VBScript File

Executable Files

XML file extension

XML File

Data Files

YUV file extension

YUV Encoded Image File

Raster Image Files

3G2 file extension

3GPP2 Multimedia File

Video Files