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

AIF file extension

Audio Interchange File Format

Audio Files

APK file extension

Android Package File

Executable Files

ASX file extension

Microsoft ASF Redirector File

Video Files

CUE file extension

Cue Sheet File

Disk Image Files

DRV file extension

Device Driver

System Files

FLV file extension

Flash Video File

Video Files

GBR file extension

Gerber File

Data Files

PKG file extension

Mac OS X Installer Package

Compressed Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

SDF file extension

Standard Data File

Data Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

TIFF file extension

Tagged Image File Format

Raster Image Files

TMP file extension

Temporary File

Backup Files

VCD file extension

Virtual CD

Disk Image Files

VOB file extension

DVD Video Object File

Video Files