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

ASF file extension

Advanced Systems Format File

Video Files

CAB file extension

Windows Cabinet File

System Files

CBR file extension

Comic Book RAR Archive

Compressed Files

DB file extension

Database File

Database Files

DXF file extension

Drawing Exchange Format File

CAD Files

FNT file extension

Windows Font File

Font Files

GAM file extension

Saved Game File

Game Files

LOG file extension

Log File

Text Files

M3U file extension

Media Playlist File

Audio Files

PIF file extension

Program Information File

Executable Files

PS file extension

PostScript File

Vector Image Files

RM file extension

Real Media File

Video Files

SYS file extension

Windows System File

System Files

ZIP file extension

Zipped File

Compressed Files

3DS file extension

3D Studio Scene

3D Image Files