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

GIF file extension

Graphical Interchange Format File

Raster Image Files

PPT file extension

PowerPoint Presentation

Data Files

KMZ file extension

Google Earth Placemark File

GIS Files

MSG file extension

Outlook Mail Message

Text Files

VCD file extension

Virtual CD

Disk Image Files

IBOOKS file extension

Multi-Touch iBook

Data Files

SWF file extension

Shockwave Flash Movie

Video Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

WAV file extension

WAVE Audio File

Audio Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

VCF file extension

vCard File

Data Files

MDF file extension

Media Disc Image File

Disk Image Files

TAR file extension

Consolidated Unix File Archive

Data Files

CPP file extension

C++ Source Code File

Developer Files

7Z file extension

7-Zip Compressed File

Compressed Files