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

ASX file extension

Microsoft ASF Redirector File

Video Files

AVI file extension

Audio Video Interleave File

Video Files

CPL file extension

Windows Control Panel Item

System Files

CUR file extension

Windows Cursor

System Files

DBF file extension

Database File

Database Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

FNT file extension

Windows Font File

Font Files

KMZ file extension

Google Earth Placemark File

GIS Files

MOBI file extension

Mobipocket eBook

eBook Files

RPM file extension

Red Hat Package Manager File

Compressed Files

RSS file extension

Rich Site Summary

Web Files

SDF file extension

Standard Data File

Data Files

SITX file extension

StuffIt X Archive

Compressed Files

TORRENT file extension

BitTorrent File

Misc Files

VCXPROJ file extension

Visual C++ Project

Developer Files