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

DEM file extension

Video Game Demo File

Game Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

INI file extension

Windows Initialization File

Settings Files

JPG file extension

JPEG Image

Raster Image Files

M file extension

Objective-C Implementation File

Developer Files

MAX file extension

3ds Max Scene File

3D Image Files

PCT file extension

Picture File

Layout Files

PIF file extension

Program Information File

Executable Files

PL file extension

Perl Script

Developer Files

PY file extension

Python Script

Developer Files

TIFF file extension

Tagged Image File Format

Raster Image Files

TXT file extension

Plain Text File

Text Files

VCF file extension

vCard File

Data Files

3DS file extension

3D Studio Scene

3D Image Files