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

SAV file extension

Saved Game

Game Files

JPG file extension

JPEG Image

Raster Image Files

ASP file extension

Active Server Page

Web Files

7Z file extension

7-Zip Compressed File

Compressed Files

PRF file extension

Outlook Profile File

Settings Files

RTF file extension

Rich Text Format File

Text Files

APK file extension

Android Package File

Executable Files

DRV file extension

Device Driver

System Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

TGA file extension

Targa Graphic

Raster Image Files

FLA file extension

Adobe Flash Animation

Developer Files

CS file extension

Visual C# Source Code File

Developer Files

APP file extension

Mac OS X Application

Executable Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

IFF file extension

Interchange File Format

Audio Files