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

TMP file extension

Temporary File

Backup Files

KEY file extension

Keynote Presentation

Data Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

PKG file extension

Mac OS X Installer Package

Compressed Files

DXF file extension

Drawing Exchange Format File

CAD Files

WSF file extension

Windows Script File

Executable Files

VCF file extension

vCard File

Data Files

DBF file extension

Database File

Database Files

7Z file extension

7-Zip Compressed File

Compressed Files

GPX file extension

GPS Exchange File

GIS Files

RSS file extension

Rich Site Summary

Web Files

XLR file extension

Works Spreadsheet

Spreadsheet Files

TORRENT file extension

BitTorrent File

Misc Files

VCD file extension

Virtual CD

Disk Image Files