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

PNG file extension

Portable Network Graphic

Raster Image Files

M4V file extension

iTunes Video File

Video Files

CFG file extension

Configuration File

Settings Files

COM file extension

DOS Command File

Executable Files

AZW file extension

Amazon Kindle eBook File

eBook Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

ASF file extension

Advanced Systems Format File

Video Files

TARGZ file extension

Compressed Tarball File

Compressed Files

BAT file extension

DOS Batch File

Executable Files

7Z file extension

7-Zip Compressed File

Compressed Files

LUA file extension

Lua Source File

Developer Files

VCD file extension

Virtual CD

Disk Image Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

INDD file extension

Adobe InDesign Document

Layout Files

GPX file extension

GPS Exchange File

GIS Files