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

APP file extension

Mac OS X Application

Executable Files

DMP file extension

Windows Memory Dump

System Files

DOC# file extension

Microsoft Word Document

Text Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

GBR file extension

Gerber File

Data Files

JAVA file extension

Java Source Code File

Developer Files

M file extension

Objective-C Implementation File

Developer Files

MPA file extension

MPEG-2 Audio File

Audio Files

ODT file extension

OpenDocument Text Document

Text Files

ROM file extension

N64 Game ROM File

Game Files

TIFF file extension

Tagged Image File Format

Raster Image Files

TTF file extension

TrueType Font

Font Files

WMV file extension

Windows Media Video File

Video Files

WSF file extension

Windows Script File

Executable Files

YUV file extension

YUV Encoded Image File

Raster Image Files