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

APP file extension

Mac OS X Application

Executable Files

CFG file extension

Configuration File

Settings Files

CS file extension

Visual C# Source Code File

Developer Files

DBF file extension

Database File

Database Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

DXF file extension

Drawing Exchange Format File

CAD Files

ICO file extension

Icon File

System Files

MOBI file extension

Mobipocket eBook

eBook Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

TEX file extension

LaTeX Source Document

Text Files

TORRENT file extension

BitTorrent File

Misc Files

VB file extension

VBScript File

Executable Files

WMA file extension

Windows Media Audio File

Audio Files

ZIP file extension

Zipped File

Compressed Files

3GP file extension

3GPP Multimedia File

Video Files