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

VCD file extension

Virtual CD

Disk Image Files

MID file extension

MIDI File

Audio Files

ASPX file extension

Active Server Page Extended File

Web Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

PHP file extension

PHP Source Code File

Web Files

7Z file extension

7-Zip Compressed File

Compressed Files

KMZ file extension

Google Earth Placemark File

GIS Files

TAR file extension

Consolidated Unix File Archive

Data Files

MSG file extension

Outlook Mail Message

Text Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

DOC# file extension

Microsoft Word Document

Text Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

M4A file extension

MPEG-4 Audio File

Audio Files

TARGZ file extension

Compressed Tarball File

Compressed Files

M3U file extension

Media Playlist File

Audio Files