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

PAGES file extension

Pages Document

Text Files

LNK file extension

Windows File Shortcut

System Files

SITX file extension

StuffIt X Archive

Compressed Files

SWF file extension

Shockwave Flash Movie

Video Files

3G2 file extension

3GPP2 Multimedia File

Video Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

MID file extension

MIDI File

Audio Files

7Z file extension

7-Zip Compressed File

Compressed Files

PNG file extension

Portable Network Graphic

Raster Image Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

CBR file extension

Comic Book RAR Archive

Compressed Files

ASP file extension

Active Server Page

Web Files

PRF file extension

Outlook Profile File

Settings Files

M3U file extension

Media Playlist File

Audio Files

PDF file extension

Portable Document Format File

Layout Files