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

PART file extension

Partially Downloaded File

Misc Files

OTF file extension

OpenType Font

Font Files

TGA file extension

Targa Graphic

Raster Image Files

FLA file extension

Adobe Flash Animation

Developer Files

ICNS file extension

Mac OS X Icon Resource File

System Files

CLASS file extension

Java Class File

Developer Files

RPM file extension

Red Hat Package Manager File

Compressed Files

KMZ file extension

Google Earth Placemark File

GIS Files

BIN file extension

Binary Disc Image

Disk Image Files

7Z file extension

7-Zip Compressed File

Compressed Files

DEM file extension

Video Game Demo File

Game Files

GZ file extension

Gnu Zipped Archive

Compressed Files

BAT file extension

DOS Batch File

Executable Files

MAX file extension

3ds Max Scene File

3D Image Files