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

VOB file extension

DVD Video Object File

Video Files

3DM file extension

Rhino 3D Model

3D Image Files

ICS file extension

iCalendar File

Misc Files

MPG file extension

MPEG Video File

Video Files

DTD file extension

Document Type Definition File

Developer Files

SDF file extension

Standard Data File

Data Files

BIN file extension

Binary Disc Image

Disk Image Files

ZIPX file extension

Extended Zip File

Compressed Files

DEM file extension

Video Game Demo File

Game Files

YUV file extension

YUV Encoded Image File

Raster Image Files

7Z file extension

7-Zip Compressed File

Compressed Files

WAV file extension

WAVE Audio File

Audio Files

ICO file extension

Icon File

System Files

LUA file extension

Lua Source File

Developer Files

PART file extension

Partially Downloaded File

Misc Files