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

GPX file extension

GPS Exchange File

GIS Files

MDF file extension

Media Disc Image File

Disk Image Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

JSP file extension

Java Server Page

Web Files

AVI file extension

Audio Video Interleave File

Video Files

7Z file extension

7-Zip Compressed File

Compressed Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

APP file extension

Mac OS X Application

Executable Files

BIN file extension

Binary Disc Image

Disk Image Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

WMV file extension

Windows Media Video File

Video Files

TEX file extension

LaTeX Source Document

Text Files

GED file extension

GEDCOM Genealogy Data File

Data Files

PY file extension

Python Script

Developer Files

INDD file extension

Adobe InDesign Document

Layout Files