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

TGA file extension

Targa Graphic

Raster Image Files

PIF file extension

Program Information File

Executable Files

APP file extension

Mac OS X Application

Executable Files

CPL file extension

Windows Control Panel Item

System Files

TIF file extension

Tagged Image File

Raster Image Files

CRX file extension

Chrome Extension

Plugin Files

PDF file extension

Portable Document Format File

Layout Files

HTML file extension

Hypertext Markup Language File

Web Files

DB file extension

Database File

Database Files

WPD file extension

WordPerfect Document

Text Files

AZW file extension

Amazon Kindle eBook File

eBook Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

WMV file extension

Windows Media Video File

Video Files

CUE file extension

Cue Sheet File

Disk Image Files

7Z file extension

7-Zip Compressed File

Compressed Files