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

TORRENT file extension

BitTorrent File

Misc Files

CRX file extension

Chrome Extension

Plugin Files

M3U file extension

Media Playlist File

Audio Files

XLSX file extension

Microsoft Excel Open XML Spreadsheet

Spreadsheet Files

PHP file extension

PHP Source Code File

Web Files

AI file extension

Adobe Illustrator File

Vector Image Files

GED file extension

GEDCOM Genealogy Data File

Data Files

JS file extension

JavaScript File

Web Files

RA file extension

Real Audio File

Audio Files

ISO file extension

Disc Image File

Disk Image Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

BIN file extension

Binary Disc Image

Disk Image Files

7Z file extension

7-Zip Compressed File

Compressed Files

CGI file extension

Common Gateway Interface Script

Executable Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files