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

7Z file extension

7-Zip Compressed File

Compressed Files

TAR file extension

Consolidated Unix File Archive

Data Files

TORRENT file extension

BitTorrent File

Misc Files

BMP file extension

Bitmap Image File

Raster Image Files

DOC# file extension

Microsoft Word Document

Text Files

OTF file extension

OpenType Font

Font Files

TGA file extension

Targa Graphic

Raster Image Files

JAR file extension

Java Archive File

Executable Files

CPL file extension

Windows Control Panel Item

System Files

ICS file extension

iCalendar File

Misc Files

3DM file extension

Rhino 3D Model

3D Image Files

HTML file extension

Hypertext Markup Language File

Web Files

MPA file extension

MPEG-2 Audio File

Audio Files

HTM file extension

Hypertext Markup Language File

Web Files

SAV file extension

Saved Game

Game Files