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

CRX file extension

Chrome Extension

Plugin Files

DBF file extension

Database File

Database Files

FLA file extension

Adobe Flash Animation

Developer Files

HTM file extension

Hypertext Markup Language File

Web Files

ISO file extension

Disc Image File

Disk Image Files

NES file extension

Nintendo (NES) ROM File

Game Files

SQL file extension

Structured Query Language Data File

Database Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

TOAST file extension

Toast Disc Image

Disk Image Files

WMA file extension

Windows Media Audio File

Audio Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

WSF file extension

Windows Script File

Executable Files

XCODEPROJ file extension

Xcode Project

Developer Files

3GP file extension

3GPP Multimedia File

Video Files