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

GADGET file extension

Windows Gadget

Executable Files

TIF file extension

Tagged Image File

Raster Image Files

XLSX file extension

Microsoft Excel Open XML Spreadsheet

Spreadsheet Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

DLL file extension

Dynamic Link Library

System Files

AIF file extension

Audio Interchange File Format

Audio Files

RPM file extension

Red Hat Package Manager File

Compressed Files

ICNS file extension

Mac OS X Icon Resource File

System Files

7Z file extension

7-Zip Compressed File

Compressed Files

DBF file extension

Database File

Database Files

ASP file extension

Active Server Page

Web Files

CRX file extension

Chrome Extension

Plugin Files

CFG file extension

Configuration File

Settings Files

EPUB file extension

Open eBook File

eBook Files

PPS file extension

PowerPoint Slide Show

Data Files