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

TOAST file extension

Toast Disc Image

Disk Image Files

VCF file extension

vCard File

Data Files

WMV file extension

Windows Media Video File

Video Files

7Z file extension

7-Zip Compressed File

Compressed Files

CGI file extension

Common Gateway Interface Script

Executable Files

DB file extension

Database File

Database Files

ZIPX file extension

Extended Zip File

Compressed Files

DDS file extension

DirectDraw Surface

Raster Image Files

VB file extension

VBScript File

Executable Files

AIF file extension

Audio Interchange File Format

Audio Files

PPS file extension

PowerPoint Slide Show

Data Files

SWF file extension

Shockwave Flash Movie

Video Files

ICS file extension

iCalendar File

Misc Files

ASPX file extension

Active Server Page Extended File

Web Files

DNG file extension

Digital Negative Image File

Camera Raw Files