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

CSR file extension

Certificate Signing Request File

Web Files

DRV file extension

Device Driver

System Files

BIN file extension

Binary Disc Image

Disk Image Files

KMZ file extension

Google Earth Placemark File

GIS Files

SWF file extension

Shockwave Flash Movie

Video Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

SITX file extension

StuffIt X Archive

Compressed Files

SAV file extension

Saved Game

Game Files

3GP file extension

3GPP Multimedia File

Video Files

ICNS file extension

Mac OS X Icon Resource File

System Files

7Z file extension

7-Zip Compressed File

Compressed Files

COM file extension

DOS Command File

Executable Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

SH file extension

Bash Shell Script

Developer Files

3DS file extension

3D Studio Scene

3D Image Files