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

EPS file extension

Encapsulated PostScript File

Vector Image Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

JAVA file extension

Java Source Code File

Developer Files

SAV file extension

Saved Game

Game Files

7Z file extension

7-Zip Compressed File

Compressed Files

YUV file extension

YUV Encoded Image File

Raster Image Files

IBOOKS file extension

Multi-Touch iBook

Data Files

M file extension

Objective-C Implementation File

Developer Files

MOBI file extension

Mobipocket eBook

eBook Files

DOC# file extension

Microsoft Word Document

Text Files

WAV file extension

WAVE Audio File

Audio Files

GZ file extension

Gnu Zipped Archive

Compressed Files

JS file extension

JavaScript File

Web Files

H file extension

C/C++/Objective-C Header File

Developer Files