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

CBR file extension

Comic Book RAR Archive

Compressed Files

VCXPROJ file extension

Visual C++ Project

Developer Files

XLSX file extension

Microsoft Excel Open XML Spreadsheet

Spreadsheet Files

CLASS file extension

Java Class File

Developer Files

DNG file extension

Digital Negative Image File

Camera Raw Files

SQL file extension

Structured Query Language Data File

Database Files

DEB file extension

Debian Software Package

Compressed Files

CPL file extension

Windows Control Panel Item

System Files

WPD file extension

WordPerfect Document

Text Files

7Z file extension

7-Zip Compressed File

Compressed Files

ASPX file extension

Active Server Page Extended File

Web Files

M4V file extension

iTunes Video File

Video Files

LNK file extension

Windows File Shortcut

System Files

JPG file extension

JPEG Image

Raster Image Files

CRX file extension

Chrome Extension

Plugin Files