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

C file extension

C/C++ Source Code File

Developer Files

CFG file extension

Configuration File

Settings Files

CGI file extension

Common Gateway Interface Script

Executable Files

CUE file extension

Cue Sheet File

Disk Image Files

M3U file extension

Media Playlist File

Audio Files

MDB file extension

Microsoft Access Database

Database Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

PPS file extension

PowerPoint Slide Show

Data Files

SRT file extension

SubRip Subtitle File

Video Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

VB file extension

VBScript File

Executable Files

WMV file extension

Windows Media Video File

Video Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

XCODEPROJ file extension

Xcode Project

Developer Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files