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

CBR file extension

Comic Book RAR Archive

Compressed Files

DDS file extension

DirectDraw Surface

Raster Image Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

DNG file extension

Digital Negative Image File

Camera Raw Files

GED file extension

GEDCOM Genealogy Data File

Data Files

KMZ file extension

Google Earth Placemark File

GIS Files

LOG file extension

Log File

Text Files

M file extension

Objective-C Implementation File

Developer Files

PPT file extension

PowerPoint Presentation

Data Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

SAV file extension

Saved Game

Game Files

TAR file extension

Consolidated Unix File Archive

Data Files

TMP file extension

Temporary File

Backup Files

VCD file extension

Virtual CD

Disk Image Files

3DS file extension

3D Studio Scene

3D Image Files