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

CFM file extension

ColdFusion Markup File

Web Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

LNK file extension

Windows File Shortcut

System Files

GZ file extension

Gnu Zipped Archive

Compressed Files

MP4 file extension

MPEG-4 Video File

Video Files

EXE file extension

Windows Executable File

Executable Files

AVI file extension

Audio Video Interleave File

Video Files

KML file extension

Keyhole Markup Language File

GIS Files

FLA file extension

Adobe Flash Animation

Developer Files

PDB file extension

Program Database

Database Files

7Z file extension

7-Zip Compressed File

Compressed Files

KEY file extension

Keynote Presentation

Data Files

CRX file extension

Chrome Extension

Plugin Files

JSP file extension

Java Server Page

Web Files

PAGES file extension

Pages Document

Text Files