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

CFG file extension

Configuration File

Settings Files

ASX file extension

Microsoft ASF Redirector File

Video Files

GZ file extension

Gnu Zipped Archive

Compressed Files

VOB file extension

DVD Video Object File

Video Files

TOAST file extension

Toast Disc Image

Disk Image Files

M3U file extension

Media Playlist File

Audio Files

DBF file extension

Database File

Database Files

YUV file extension

YUV Encoded Image File

Raster Image Files

GIF file extension

Graphical Interchange Format File

Raster Image Files

7Z file extension

7-Zip Compressed File

Compressed Files

MAX file extension

3ds Max Scene File

3D Image Files

MP4 file extension

MPEG-4 Video File

Video Files

TTF file extension

TrueType Font

Font Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

PDB file extension

Program Database

Database Files