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

AZW file extension

Amazon Kindle eBook File

eBook Files

EPUB file extension

Open eBook File

eBook Files

INI file extension

Windows Initialization File

Settings Files

JSP file extension

Java Server Page

Web Files

LNK file extension

Windows File Shortcut

System Files

PART file extension

Partially Downloaded File

Misc Files

PRF file extension

Outlook Profile File

Settings Files

ROM file extension

N64 Game ROM File

Game Files

SAV file extension

Saved Game

Game Files

SLN file extension

Visual Studio Solution File

Developer Files

TAR file extension

Consolidated Unix File Archive

Data Files

TEX file extension

LaTeX Source Document

Text Files

VOB file extension

DVD Video Object File

Video Files

WMA file extension

Windows Media Audio File

Audio Files

XHTML file extension

Extensible Hypertext Markup Language File

Web Files