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

BIN file extension

Binary Disc Image

Disk Image Files

CBR file extension

Comic Book RAR Archive

Compressed Files

CSS file extension

Cascading Style Sheet

Web Files

EPUB file extension

Open eBook File

eBook Files

GAM file extension

Saved Game File

Game Files

H file extension

C/C++/Objective-C Header File

Developer Files

JAVA file extension

Java Source Code File

Developer Files

M file extension

Objective-C Implementation File

Developer Files

MP3 file extension

MP3 Audio File

Audio Files

ODT file extension

OpenDocument Text Document

Text Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

SLN file extension

Visual Studio Solution File

Developer Files

UUE file extension

Uuencoded File

Encoded Files

VB file extension

VBScript File

Executable Files

WMV file extension

Windows Media Video File

Video Files