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

ASP file extension

Active Server Page

Web Files

AZW file extension

Amazon Kindle eBook File

eBook Files

CUR file extension

Windows Cursor

System Files

DRV file extension

Device Driver

System Files

GADGET file extension

Windows Gadget

Executable Files

LNK file extension

Windows File Shortcut

System Files

M4V file extension

iTunes Video File

Video Files

NES file extension

Nintendo (NES) ROM File

Game Files

PART file extension

Partially Downloaded File

Misc Files

RA file extension

Real Audio File

Audio Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

RPM file extension

Red Hat Package Manager File

Compressed Files

SYS file extension

Windows System File

System Files

XCODEPROJ file extension

Xcode Project

Developer Files

ZIPX file extension

Extended Zip File

Compressed Files