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

PPTX file extension

PowerPoint Open XML Presentation

Data Files

KMZ file extension

Google Earth Placemark File

GIS Files

DEB file extension

Debian Software Package

Compressed Files

BIN file extension

Binary Disc Image

Disk Image Files

ASX file extension

Microsoft ASF Redirector File

Video Files

GPX file extension

GPS Exchange File

GIS Files

TARGZ file extension

Compressed Tarball File

Compressed Files

M4A file extension

MPEG-4 Audio File

Audio Files

7Z file extension

7-Zip Compressed File

Compressed Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

MID file extension

MIDI File

Audio Files

LNK file extension

Windows File Shortcut

System Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

COM file extension

DOS Command File

Executable Files

TIF file extension

Tagged Image File

Raster Image Files