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

BAK file extension

Backup File

Backup Files

CAB file extension

Windows Cabinet File

System Files

CRX file extension

Chrome Extension

Plugin Files

CUR file extension

Windows Cursor

System Files

GAM file extension

Saved Game File

Game Files

INI file extension

Windows Initialization File

Settings Files

JSP file extension

Java Server Page

Web Files

LNK file extension

Windows File Shortcut

System Files

MID file extension

MIDI File

Audio Files

PHP file extension

PHP Source Code File

Web Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

TAR file extension

Consolidated Unix File Archive

Data Files

UUE file extension

Uuencoded File

Encoded Files

WAV file extension

WAVE Audio File

Audio Files

WMA file extension

Windows Media Audio File

Audio Files