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

AIF file extension

Audio Interchange File Format

Audio Files

AVI file extension

Audio Video Interleave File

Video Files

C file extension

C/C++ Source Code File

Developer Files

CER file extension

Internet Security Certificate

Web Files

DNG file extension

Digital Negative Image File

Camera Raw Files

JAVA file extension

Java Source Code File

Developer Files

KML file extension

Keyhole Markup Language File

GIS Files

LUA file extension

Lua Source File

Developer Files

MDB file extension

Microsoft Access Database

Database Files

PDB file extension

Program Database

Database Files

PPS file extension

PowerPoint Slide Show

Data Files

PY file extension

Python Script

Developer Files

ROM file extension

N64 Game ROM File

Game Files

SLN file extension

Visual Studio Solution File

Developer Files

TIF file extension

Tagged Image File

Raster Image Files