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

FLA file extension

Adobe Flash Animation

Developer Files

DAT file extension

Data File

Data Files

RTF file extension

Rich Text Format File

Text Files

TORRENT file extension

BitTorrent File

Misc Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

TTF file extension

TrueType Font

Font Files

HTM file extension

Hypertext Markup Language File

Web Files

ACCDB file extension

Access 2007 Database File

Database Files

AZW file extension

Amazon Kindle eBook File

eBook Files

CSS file extension

Cascading Style Sheet

Web Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

PIF file extension

Program Information File

Executable Files

7Z file extension

7-Zip Compressed File

Compressed Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

ROM file extension

N64 Game ROM File

Game Files