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

GADGET file extension

Windows Gadget

Executable Files

FLA file extension

Adobe Flash Animation

Developer Files

RA file extension

Real Audio File

Audio Files

M4V file extension

iTunes Video File

Video Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

WMV file extension

Windows Media Video File

Video Files

APP file extension

Mac OS X Application

Executable Files

TGA file extension

Targa Graphic

Raster Image Files

LOG file extension

Log File

Text Files

7Z file extension

7-Zip Compressed File

Compressed Files

ICNS file extension

Mac OS X Icon Resource File

System Files

MDB file extension

Microsoft Access Database

Database Files

DNG file extension

Digital Negative Image File

Camera Raw Files

AI file extension

Adobe Illustrator File

Vector Image Files

SAV file extension

Saved Game

Game Files