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

APP file extension

Mac OS X Application

Executable Files

CER file extension

Internet Security Certificate

Web Files

CRX file extension

Chrome Extension

Plugin Files

DBF file extension

Database File

Database Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

GIF file extension

Graphical Interchange Format File

Raster Image Files

MDB file extension

Microsoft Access Database

Database Files

MID file extension

MIDI File

Audio Files

MP4 file extension

MPEG-4 Video File

Video Files

PHP file extension

PHP Source Code File

Web Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

TGA file extension

Targa Graphic

Raster Image Files

TIF file extension

Tagged Image File

Raster Image Files

VCXPROJ file extension

Visual C++ Project

Developer Files