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

DBF file extension

Database File

Database Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

DMP file extension

Windows Memory Dump

System Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

IBOOKS file extension

Multi-Touch iBook

Data Files

ISO file extension

Disc Image File

Disk Image Files

KEY file extension

Keynote Presentation

Data Files

LNK file extension

Windows File Shortcut

System Files

PIF file extension

Program Information File

Executable Files

SDF file extension

Standard Data File

Data Files

TIF file extension

Tagged Image File

Raster Image Files

VCXPROJ file extension

Visual C++ Project

Developer Files

WAV file extension

WAVE Audio File

Audio Files