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

C file extension

C/C++ Source Code File

Developer Files

CAB file extension

Windows Cabinet File

System Files

CPL file extension

Windows Control Panel Item

System Files

DB file extension

Database File

Database Files

ICO file extension

Icon File

System Files

KMZ file extension

Google Earth Placemark File

GIS Files

MID file extension

MIDI File

Audio Files

ODT file extension

OpenDocument Text Document

Text Files

PL file extension

Perl Script

Developer Files

PPT file extension

PowerPoint Presentation

Data Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

UUE file extension

Uuencoded File

Encoded Files

VCF file extension

vCard File

Data Files

VOB file extension

DVD Video Object File

Video Files

3GP file extension

3GPP Multimedia File

Video Files