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

AVI file extension

Audio Video Interleave File

Video Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files

MID file extension

MIDI File

Audio Files

GAM file extension

Saved Game File

Game Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

DNG file extension

Digital Negative Image File

Camera Raw Files

ROM file extension

N64 Game ROM File

Game Files

COM file extension

DOS Command File

Executable Files

CRX file extension

Chrome Extension

Plugin Files

PDF file extension

Portable Document Format File

Layout Files

TIFF file extension

Tagged Image File Format

Raster Image Files

GED file extension

GEDCOM Genealogy Data File

Data Files

MPG file extension

MPEG Video File

Video Files

7Z file extension

7-Zip Compressed File

Compressed Files