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

HTML file extension

Hypertext Markup Language File

Web Files

ROM file extension

N64 Game ROM File

Game Files

DB file extension

Database File

Database Files

ACCDB file extension

Access 2007 Database File

Database Files

GAM file extension

Saved Game File

Game Files

VCD file extension

Virtual CD

Disk Image Files

7Z file extension

7-Zip Compressed File

Compressed Files

ICS file extension

iCalendar File

Misc Files

FON file extension

Generic Font File

Font Files

PPT file extension

PowerPoint Presentation

Data Files

KMZ file extension

Google Earth Placemark File

GIS Files

INDD file extension

Adobe InDesign Document

Layout Files

SH file extension

Bash Shell Script

Developer Files

TOAST file extension

Toast Disc Image

Disk Image Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files