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

BAT file extension

DOS Batch File

Executable Files

CAB file extension

Windows Cabinet File

System Files

DAT file extension

Data File

Data Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

EXE file extension

Windows Executable File

Executable Files

PL file extension

Perl Script

Developer Files

PPT file extension

PowerPoint Presentation

Data Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

RM file extension

Real Media File

Video Files

SRT file extension

SubRip Subtitle File

Video Files

VB file extension

VBScript File

Executable Files

WPD file extension

WordPerfect Document

Text Files

XCODEPROJ file extension

Xcode Project

Developer Files

3GP file extension

3GPP Multimedia File

Video Files