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

OTF file extension

OpenType Font

Font Files

7Z file extension

7-Zip Compressed File

Compressed Files

TIF file extension

Tagged Image File

Raster Image Files

CBR file extension

Comic Book RAR Archive

Compressed Files

SWF file extension

Shockwave Flash Movie

Video Files

WMV file extension

Windows Media Video File

Video Files

FLA file extension

Adobe Flash Animation

Developer Files

PNG file extension

Portable Network Graphic

Raster Image Files

PDF file extension

Portable Document Format File

Layout Files

MSG file extension

Outlook Mail Message

Text Files

CPL file extension

Windows Control Panel Item

System Files

MPG file extension

MPEG Video File

Video Files

ZIPX file extension

Extended Zip File

Compressed Files

DLL file extension

Dynamic Link Library

System Files

TORRENT file extension

BitTorrent File

Misc Files