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

AVI file extension

Audio Video Interleave File

Video Files

BIN file extension

Binary Disc Image

Disk Image Files

CSS file extension

Cascading Style Sheet

Web Files

FNT file extension

Windows Font File

Font Files

H file extension

C/C++/Objective-C Header File

Developer Files

JAVA file extension

Java Source Code File

Developer Files

M3U file extension

Media Playlist File

Audio Files

M4V file extension

iTunes Video File

Video Files

MPG file extension

MPEG Video File

Video Files

PPT file extension

PowerPoint Presentation

Data Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

SLN file extension

Visual Studio Solution File

Developer Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

WMA file extension

Windows Media Audio File

Audio Files

WPS file extension

Microsoft Works Word Processor Document

Text Files