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

ASX file extension

Microsoft ASF Redirector File

Video Files

C file extension

C/C++ Source Code File

Developer Files

DB file extension

Database File

Database Files

DXF file extension

Drawing Exchange Format File

CAD Files

GAM file extension

Saved Game File

Game Files

GED file extension

GEDCOM Genealogy Data File

Data Files

HTML file extension

Hypertext Markup Language File

Web Files

MSG file extension

Outlook Mail Message

Text Files

SAV file extension

Saved Game

Game Files

TEX file extension

LaTeX Source Document

Text Files

THM file extension

Thumbnail Image File

Raster Image Files

TIF file extension

Tagged Image File

Raster Image Files

WMV file extension

Windows Media Video File

Video Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files

XLSX file extension

Microsoft Excel Open XML Spreadsheet

Spreadsheet Files