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

APK file extension

Android Package File

Executable Files

AZW file extension

Amazon Kindle eBook File

eBook Files

BIN file extension

Binary Disc Image

Disk Image Files

BMP file extension

Bitmap Image File

Raster Image Files

DOC# file extension

Microsoft Word Document

Text Files

GADGET file extension

Windows Gadget

Executable Files

ICS file extension

iCalendar File

Misc Files

KML file extension

Keyhole Markup Language File

GIS Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

MPG file extension

MPEG Video File

Video Files

PAGES file extension

Pages Document

Text Files

SAV file extension

Saved Game

Game Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

SYS file extension

Windows System File

System Files

3G2 file extension

3GPP2 Multimedia File

Video Files