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

PIF file extension

Program Information File

Executable Files

GPX file extension

GPS Exchange File

GIS Files

PRF file extension

Outlook Profile File

Settings Files

GADGET file extension

Windows Gadget

Executable Files

PAGES file extension

Pages Document

Text Files

7Z file extension

7-Zip Compressed File

Compressed Files

LOG file extension

Log File

Text Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

ODT file extension

OpenDocument Text Document

Text Files

DEB file extension

Debian Software Package

Compressed Files

VOB file extension

DVD Video Object File

Video Files

FNT file extension

Windows Font File

Font Files

COM file extension

DOS Command File

Executable Files

KML file extension

Keyhole Markup Language File

GIS Files

ASX file extension

Microsoft ASF Redirector File

Video Files