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

CRX file extension

Chrome Extension

Plugin Files

CSV file extension

Comma Separated Values File

Data Files

DBF file extension

Database File

Database Files

DEB file extension

Debian Software Package

Compressed Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

FLA file extension

Adobe Flash Animation

Developer Files

GIF file extension

Graphical Interchange Format File

Raster Image Files

LOG file extension

Log File

Text Files

MID file extension

MIDI File

Audio Files

ODT file extension

OpenDocument Text Document

Text Files

PHP file extension

PHP Source Code File

Web Files

ROM file extension

N64 Game ROM File

Game Files

VCF file extension

vCard File

Data Files

XML file extension

XML File

Data Files

YUV file extension

YUV Encoded Image File

Raster Image Files