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

MID file extension

MIDI File

Audio Files

DB file extension

Database File

Database Files

DEB file extension

Debian Software Package

Compressed Files

ROM file extension

N64 Game ROM File

Game Files

NES file extension

Nintendo (NES) ROM File

Game Files

JS file extension

JavaScript File

Web Files

RA file extension

Real Audio File

Audio Files

VOB file extension

DVD Video Object File

Video Files

YUV file extension

YUV Encoded Image File

Raster Image Files

WSF file extension

Windows Script File

Executable Files

TIF file extension

Tagged Image File

Raster Image Files

MP4 file extension

MPEG-4 Video File

Video Files

ASPX file extension

Active Server Page Extended File

Web Files

AI file extension

Adobe Illustrator File

Vector Image Files

7Z file extension

7-Zip Compressed File

Compressed Files